Professional Team Foundation Server 2010
A new book on Team Foundation server has just recently been released. It’s an in-depth view of using the breadth of TFS 2010 capabilities and includes a lot of information on customizing and extending TFS.
I know the authors well (2 of them are on our team :)) and I can’t think of a better group of people to write the definitive work on TFS. I recommend it for everyone responsible for managing a development process with TFS.