Added basic support for PageNumber and PageCount place holders.

When inserted into a Header or Footer Word will automatically display the correct value foreach page.

Word will not automatically update these place holders if inserted inside a document level Paragraph. 
You need to right click and select update field. I therefore suggest that you only use these place holders inside Headers and Footers.

Added
-------

Paragraph.AppendPageNumber(PageNumberFormat)
Paragraph.InsertPageNumber(PageNumberFormat, int index)

Paragraph.AppendPageCount(PageNumberFormat)
Paragraph.InsertPageCount(PageNumberFormat, int index)

Example
-----------
// Create a new document.
using (DocX document = DocX.Create(@"Test.docx"))
{
    // Add Headers to the document.
    document.AddHeaders();

    // Get the default Header.
    Header header = document.Headers.odd;

    // Insert a Paragraph into the Header.
    Paragraph p0 = header.InsertParagraph();

    // Append place holders for PageNumber and PageCount into the Header.
    // Word will replace these with the correct value foreach Page.
    p0.Append("Page (");
    p0.AppendPageNumber(PageNumberFormat.normal);
    p0.Append(" of ");
    p0.AppendPageCount(PageNumberFormat.normal);
    p0.Append(")");

    // Save the document.
    document.Save();
}

DocX/Container.cs

@@ -86,6 +86,10 @@ namespace Novacode
 
         internal void GetParagraphsRecursive(XElement Xml, ref int index, ref List<Paragraph> paragraphs)
         {
+            // sdtContent are for PageNumbers inside Headers or Footers, don't go any deeper.
+            if (Xml.Name.LocalName == "sdtContent")
+                return;
+
             if (Xml.Name.LocalName == "p")
             {
                 paragraphs.Add(new Paragraph(Document, Xml, index));

DocX/DocX.cs

@@ -27,6 +27,27 @@ namespace Novacode
         static internal XNamespace customVTypesSchema = "http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes";
         #endregion
 
+        /// <summary>
+        /// Returns true if any editing restrictions are imposed on this document.
+        /// </summary>
+        /// <example>
+        /// <code>
+        /// // Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     if(document.isProtected)
+        ///         Console.WriteLine("Protected");
+        ///     else
+        ///         Console.WriteLine("Not protected");
+        ///         
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="AddProtection"/>
+        /// <seealso cref="RemoveProtection"/>
+        /// <seealso cref="GetProtectionType"/>
         public bool isProtected
         {
             get
@@ -35,6 +56,33 @@ namespace Novacode
             }
         }
 
+        /// <summary>
+        /// Returns the type of editing protection imposed on this document.
+        /// </summary>
+        /// <returns>The type of editing protection imposed on this document.</returns>
+        /// <example>
+        /// <code>
+        /// Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     // Make sure the document is protected before checking the protection type.
+        ///     if (document.isProtected)
+        ///     {
+        ///         EditRestrictions protection = document.GetProtectionType();
+        ///         Console.WriteLine("Document is protected using " + protection.ToString());
+        ///     }
+        ///
+        ///     else
+        ///         Console.WriteLine("Document is not protected.");
+        ///
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="AddProtection"/>
+        /// <seealso cref="RemoveProtection"/>
+        /// <seealso cref="isProtected"/>
         public EditRestrictions GetProtectionType()
         {
             if (isProtected)
@@ -47,6 +95,26 @@ namespace Novacode
             return EditRestrictions.none;
         }
 
+        /// <summary>
+        /// Add editing protection to this document. 
+        /// </summary>
+        /// <param name="er">The type of protection to add to this document.</param>
+        /// <example>
+        /// <code>
+        /// // Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     // Allow no editing, only the adding of comment.
+        ///     document.AddProtection(EditRestrictions.comments);
+        ///     
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="RemoveProtection"/>
+        /// <seealso cref="GetProtectionType"/>
+        /// <seealso cref="isProtected"/>
         public void AddProtection(EditRestrictions er)
         {
             // Call remove protection before adding a new protection element.
@@ -61,7 +129,26 @@ namespace Novacode
 
             settings.Root.AddFirst(documentProtection);
         }
-
+       
+        /// <summary>
+        /// Remove editing protection from this document.
+        /// </summary>
+        /// <example>
+        /// <code>
+        /// // Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     // Remove any editing restrictions that are imposed on this document.
+        ///     document.RemoveProtection();
+        ///
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="AddProtection"/>
+        /// <seealso cref="GetProtectionType"/>
+        /// <seealso cref="isProtected"/>
         public void RemoveProtection()
         {
             // Remove every node of type documentProtection.

DocX/Footer.cs

@@ -9,6 +9,47 @@ namespace Novacode
 {
     public class Footer : Container
     {
+        public bool PageNumbers 
+        { 
+            get
+            {
+                return false;
+            }
+            
+            set 
+            {
+                XElement e = XElement.Parse
+                (@"<w:sdt xmlns:w='http://schemas.openxmlformats.org/wordprocessingml/2006/main'>
+                    <w:sdtPr>
+                      <w:id w:val='157571950' />
+                      <w:docPartObj>
+                        <w:docPartGallery w:val='Page Numbers (Top of Page)' />
+                        <w:docPartUnique />
+                      </w:docPartObj>
+                    </w:sdtPr>
+                    <w:sdtContent>
+                      <w:p w:rsidR='008D2BFB' w:rsidRDefault='008D2BFB'>
+                        <w:pPr>
+                          <w:pStyle w:val='Header' />
+                          <w:jc w:val='center' />
+                        </w:pPr>
+                        <w:fldSimple w:instr=' PAGE \* MERGEFORMAT'>
+                          <w:r>
+                            <w:rPr>
+                              <w:noProof />
+                            </w:rPr>
+                            <w:t>1</w:t>
+                          </w:r>
+                        </w:fldSimple>
+                      </w:p>
+                    </w:sdtContent>
+                  </w:sdt>"
+               );
+
+                Xml.AddFirst(e);
+            }
+        }
+
         internal PackagePart mainPart;
         internal Footer(DocX document, XElement xml, PackagePart mainPart): base(document, xml)
         {

DocX/Header.cs

@@ -9,6 +9,51 @@ namespace Novacode
 {
     public class Header : Container
     {
+        public bool PageNumbers
+        {
+            get
+            {
+                return false;
+            }
+
+            set
+            {
+                XElement e = XElement.Parse
+                (@"<w:sdt xmlns:w='http://schemas.openxmlformats.org/wordprocessingml/2006/main'>
+                    <w:sdtPr>
+                      <w:id w:val='157571950' />
+                      <w:docPartObj>
+                        <w:docPartGallery w:val='Page Numbers (Top of Page)' />
+                        <w:docPartUnique />
+                      </w:docPartObj>
+                    </w:sdtPr>
+                    <w:sdtContent>
+                      <w:p w:rsidR='008D2BFB' w:rsidRDefault='008D2BFB'>
+                        <w:pPr>
+                          <w:pStyle w:val='Header' />
+                          <w:jc w:val='center' />
+                        </w:pPr>
+                        <w:fldSimple w:instr=' PAGE \* MERGEFORMAT'>
+                          <w:r>
+                            <w:rPr>
+                              <w:noProof />
+                            </w:rPr>
+                            <w:t>1</w:t>
+                          </w:r>
+                        </w:fldSimple>
+                      </w:p>
+                    </w:sdtContent>
+                  </w:sdt>"
+               );
+               
+               Xml.AddFirst(e);
+               
+               PageNumberParagraph = new Paragraph(Document, e.Descendants(XName.Get("p", DocX.w.NamespaceName)).SingleOrDefault(), 0); 
+            }
+        }
+
+        public Paragraph PageNumberParagraph;
+
         internal PackagePart mainPart;
         internal Header(DocX document, XElement xml, PackagePart mainPart):base(document, xml)
         {

DocX/Paragraph.cs

@@ -1789,16 +1789,23 @@ namespace Novacode
                             if (trackChanges && !parentElement.Name.LocalName.Equals("ins"))
                                 insert = CreateEdit(EditType.ins, insert_datetime, newRuns);
 
-                            // Split this run at the point you want to insert
-                            XElement[] splitRun = Run.SplitRun(run, index);
+                            // Special case to deal with Page Number elements.
+                            if (parentElement.Name.LocalName.Equals("fldSimple"))
+                                parentElement.AddBeforeSelf(insert);
 
-                            // Replace the origional run
-                            run.Xml.ReplaceWith
-                            (
-                                splitRun[0],
-                                insert,
-                                splitRun[1]
-                            );
+                            else
+                            {
+                                // Split this run at the point you want to insert
+                                XElement[] splitRun = Run.SplitRun(run, index);
+
+                                // Replace the origional run
+                                run.Xml.ReplaceWith
+                                (
+                                    splitRun[0],
+                                    insert,
+                                    splitRun[1]
+                                );
+                            }
 
                             break;
                         }
@@ -3162,6 +3169,260 @@ namespace Novacode
 
             return query;
         }
+
+        /// <summary>
+        /// Insert a PageNumber place holder into a Paragraph.
+        /// This place holder should only be inserted into a Header or Footer Paragraph.
+        /// Word will not automatically update this field if it is inserted into a document level Paragraph.
+        /// </summary>
+        /// <param name="pnf">The PageNumberFormat can be normal: (1, 2, ...) or Roman: (I, II, ...)</param>
+        /// <param name="index">The text index to insert this PageNumber place holder at.</param>
+        /// <example>
+        /// <code>
+        /// // Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     // Add Headers to the document.
+        ///     document.AddHeaders();
+        ///
+        ///     // Get the default Header.
+        ///     Header header = document.Headers.odd;
+        ///
+        ///     // Insert a Paragraph into the Header.
+        ///     Paragraph p0 = header.InsertParagraph("Page ( of )");
+        ///
+        ///     // Insert place holders for PageNumber and PageCount into the Header.
+        ///     // Word will replace these with the correct value for each Page.
+        ///     p0.InsertPageNumber(PageNumberFormat.normal, 6);
+        ///     p0.InsertPageCount(PageNumberFormat.normal, 11);
+        ///
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="AppendPageCount"/>
+        /// <seealso cref="AppendPageNumber"/>
+        /// <seealso cref="InsertPageCount"/>
+        public void InsertPageNumber(PageNumberFormat pnf, int index = 0)
+        {
+            XElement fldSimple = new XElement(XName.Get("fldSimple", DocX.w.NamespaceName));
+
+            if (pnf == PageNumberFormat.normal)
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" PAGE   \* MERGEFORMAT "));
+            else
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" PAGE  \* ROMAN  \* MERGEFORMAT "));
+
+            XElement content = XElement.Parse
+            (
+             @"<w:r w:rsidR='001D0226' xmlns:w=""http://schemas.openxmlformats.org/wordprocessingml/2006/main"">
+                   <w:rPr>
+                       <w:noProof /> 
+                   </w:rPr>
+                   <w:t>1</w:t> 
+               </w:r>"
+            );
+
+            fldSimple.Add(content);
+
+            if (index == 0)
+                Xml.AddFirst(fldSimple);
+            else
+            {
+                Run r = GetFirstRunEffectedByEdit(index, EditType.ins);
+                XElement[] splitEdit = SplitEdit(r.Xml, index, EditType.ins);
+                r.Xml.ReplaceWith
+                (
+                    splitEdit[0],
+                    fldSimple,
+                    splitEdit[1]
+                );
+            }
+        }
+
+        /// <summary>
+        /// Append a PageNumber place holder onto the end of a Paragraph.
+        /// </summary>
+        /// <param name="pnf">The PageNumberFormat can be normal: (1, 2, ...) or Roman: (I, II, ...)</param>
+        /// <example>
+        /// <code>
+        /// // Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     // Add Headers to the document.
+        ///     document.AddHeaders();
+        ///
+        ///     // Get the default Header.
+        ///     Header header = document.Headers.odd;
+        ///
+        ///     // Insert a Paragraph into the Header.
+        ///     Paragraph p0 = header.InsertParagraph();
+        ///
+        ///     // Appemd place holders for PageNumber and PageCount into the Header.
+        ///     // Word will replace these with the correct value for each Page.
+        ///     p0.Append("Page (");
+        ///     p0.AppendPageNumber(PageNumberFormat.normal);
+        ///     p0.Append(" of ");
+        ///     p0.AppendPageCount(PageNumberFormat.normal);
+        ///     p0.Append(")");
+        /// 
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="AppendPageCount"/>
+        /// <seealso cref="InsertPageNumber"/>
+        /// <seealso cref="InsertPageCount"/>
+        public void AppendPageNumber(PageNumberFormat pnf)
+        {
+            XElement fldSimple = new XElement(XName.Get("fldSimple", DocX.w.NamespaceName));
+            
+            if(pnf == PageNumberFormat.normal)
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" PAGE   \* MERGEFORMAT "));
+            else
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" PAGE  \* ROMAN  \* MERGEFORMAT "));
+
+            XElement content = XElement.Parse
+            (
+             @"<w:r w:rsidR='001D0226' xmlns:w=""http://schemas.openxmlformats.org/wordprocessingml/2006/main"">
+                   <w:rPr>
+                       <w:noProof /> 
+                   </w:rPr>
+                   <w:t>1</w:t> 
+               </w:r>"
+            );
+
+            fldSimple.Add(content);
+            Xml.Add(fldSimple);
+        }
+
+        /// <summary>
+        /// Insert a PageCount place holder into a Paragraph.
+        /// This place holder should only be inserted into a Header or Footer Paragraph.
+        /// Word will not automatically update this field if it is inserted into a document level Paragraph.
+        /// </summary>
+        /// <param name="pnf">The PageNumberFormat can be normal: (1, 2, ...) or Roman: (I, II, ...)</param>
+        /// <param name="index">The text index to insert this PageCount place holder at.</param>
+        /// <example>
+        /// <code>
+        /// // Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     // Add Headers to the document.
+        ///     document.AddHeaders();
+        ///
+        ///     // Get the default Header.
+        ///     Header header = document.Headers.odd;
+        ///
+        ///     // Insert a Paragraph into the Header.
+        ///     Paragraph p0 = header.InsertParagraph("Page ( of )");
+        ///
+        ///     // Insert place holders for PageNumber and PageCount into the Header.
+        ///     // Word will replace these with the correct value for each Page.
+        ///     p0.InsertPageNumber(PageNumberFormat.normal, 6);
+        ///     p0.InsertPageCount(PageNumberFormat.normal, 11);
+        ///
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="AppendPageCount"/>
+        /// <seealso cref="AppendPageNumber"/>
+        /// <seealso cref="InsertPageNumber"/>
+        public void InsertPageCount(PageNumberFormat pnf, int index = 0)
+        {
+            XElement fldSimple = new XElement(XName.Get("fldSimple", DocX.w.NamespaceName));
+
+            if (pnf == PageNumberFormat.normal)
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" NUMPAGES   \* MERGEFORMAT "));
+            else
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" NUMPAGES  \* ROMAN  \* MERGEFORMAT "));
+
+            XElement content = XElement.Parse
+            (
+             @"<w:r w:rsidR='001D0226' xmlns:w=""http://schemas.openxmlformats.org/wordprocessingml/2006/main"">
+                   <w:rPr>
+                       <w:noProof /> 
+                   </w:rPr>
+                   <w:t>1</w:t> 
+               </w:r>"
+            );
+
+            fldSimple.Add(content);
+
+            if (index == 0)
+                Xml.AddFirst(fldSimple);
+            else
+            {
+                Run r = GetFirstRunEffectedByEdit(index, EditType.ins);
+                XElement[] splitEdit = SplitEdit(r.Xml, index, EditType.ins);
+                r.Xml.ReplaceWith
+                (
+                    splitEdit[0],
+                    fldSimple,
+                    splitEdit[1]
+                );
+            }
+        }
+
+        /// <summary>
+        /// Append a PageCount place holder onto the end of a Paragraph.
+        /// </summary>
+        /// <param name="pnf">The PageNumberFormat can be normal: (1, 2, ...) or Roman: (I, II, ...)</param>
+        /// <example>
+        /// <code>
+        /// // Create a new document.
+        /// using (DocX document = DocX.Create(@"Test.docx"))
+        /// {
+        ///     // Add Headers to the document.
+        ///     document.AddHeaders();
+        ///
+        ///     // Get the default Header.
+        ///     Header header = document.Headers.odd;
+        ///
+        ///     // Insert a Paragraph into the Header.
+        ///     Paragraph p0 = header.InsertParagraph();
+        ///
+        ///     // Appemd place holders for PageNumber and PageCount into the Header.
+        ///     // Word will replace these with the correct value for each Page.
+        ///     p0.Append("Page (");
+        ///     p0.AppendPageNumber(PageNumberFormat.normal);
+        ///     p0.Append(" of ");
+        ///     p0.AppendPageCount(PageNumberFormat.normal);
+        ///     p0.Append(")");
+        /// 
+        ///     // Save the document.
+        ///     document.Save();
+        /// }
+        /// </code>
+        /// </example>
+        /// <seealso cref="AppendPageNumber"/>
+        /// <seealso cref="InsertPageNumber"/>
+        /// <seealso cref="InsertPageCount"/>
+        public void AppendPageCount(PageNumberFormat pnf)
+        {
+            XElement fldSimple = new XElement(XName.Get("fldSimple", DocX.w.NamespaceName));
+
+            if (pnf == PageNumberFormat.normal)
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" NUMPAGES   \* MERGEFORMAT "));
+            else
+                fldSimple.Add(new XAttribute(XName.Get("instr", DocX.w.NamespaceName), @" NUMPAGES  \* ROMAN  \* MERGEFORMAT "));
+
+            XElement content = XElement.Parse
+            (
+             @"<w:r w:rsidR='001D0226' xmlns:w=""http://schemas.openxmlformats.org/wordprocessingml/2006/main"">
+                   <w:rPr>
+                       <w:noProof /> 
+                   </w:rPr>
+                   <w:t>1</w:t> 
+               </w:r>"
+            );
+
+            fldSimple.Add(content);
+            Xml.Add(fldSimple);
+        }
     }
 
     public class Run : DocXElement

DocX/_Enumerations.cs

@@ -5,6 +5,12 @@ using System.Text;
 
 namespace Novacode
 {
+    public enum PageNumberFormat
+    {
+        normal,
+        roman
+    }
+
     public enum BorderSize
     {
         one,