A few things before we get started:

1. You will need the HTML Help Workshop installed
2. September CTP of Sandcastle
3. My September CTP Sandcastle Targets File (attached)
   This file needs to be copied to your %programfiles%\MSBuild directory

Next you will need to make some modifications to the standard configuration file (I am using the VS2005 style)

1. Make a copy of %programfiles%\Sandcastle\Presentation\vs2005\configuration\sandcastle.config
2. Change references of
   1. ..\..\ to %programfiles%\sandcastle\
   2. ..\cpref_reflection to %programfiles%\sandcastle\examples\cpref_reflection

Update your TFSBuild.proj to include the following:

1. Add a new Import tag referencing the sandcastle targets file
2. Add a new target called DocumentCLR
   <Target Name="DocumentCLR">
   <CallTarget Targets="SandcastleDocument" ContinueOnError="false" />
   <MakeDir Condition="!Exists('$(BinariesRoot)\Documentation')" Directories="$(BinariesRoot)\Documentation" ContinueOnError="false" />
   <Copy SourceFiles="$(SandcastleWorkingDirectory)\Output\$(SandcastleDocumentationName).chm" DestinationFiles="$(BinariesRoot)\Documentation\$(SandcastleDocumentationName).chm" ContinueOnError="false"/>
   </Target>
3. Add an additional target that overrides the AfterCompile target
   <Target Name="AfterCompile">
   <CallTarget RunEachTargetSeparately="true" Targets="DocumentCLR" ContinueOnError="false"/>
   <OnError ExecuteTargets=" OnBuildBreak;"/>
   </Target>
4. Update your TFSBuild.rsp file to include some configuration
   /p:SandcastleDocumentationName=NameOfYourCHM
   /p:SandcastleConfiguration="C:\Path_TO_MODIFIED_CONFIG\sandcastle.config"
   /p:SandcastleDocumentationOutput=$(BinariesRoot)\Documentation
   /p:SandcastleDependencies="%windir%\Microsoft.NET\Framework\v2.0.50727\*.dll,\\lcabuildvm01\3rdParty\Dependencies\*.dll,%windir%\assembly\GAC_MSIL\Microsoft.VisualStudio.QualityTools.UnitTestFramework\8.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll"
   /p:SandcastleHelpGeneration=CHM