From the contents:
- Team Foundation Server Extensibility
- Team Foundation Server SDK Architecture
- How to: Run Team Foundation Server SDK Samples
- Team Foundation Core Services
- Work Item Tracking Extensibility
- Source Control Extensibility
- Data Warehouse Extensibility
- Reference for Team Foundation Server SDK
Link: http://msdn2.microsoft.com/en-us/library/bb130146(VS.80).aspx
To get the 2010 version, you need to download the .chm “Public Object Model” from http://code.msdn.microsoft.com/TfsSdk