When you install the RTM (release to manufacturing) release of Team Explorer, you should be certain to install the updated MSDN Library, which includes the RTM documentation for Team Foundation. Otherwise, you will encounter content that is outdated and potentially inaccurate. This version of the MSDN Library should appear in MSDN subscriber (and volume licensing) downloads alongside Team Foundation Server.
You can spot outdated Team Foundation topics by a note that appears at the top of indicating that it is prerelease documentation:
[This topic is pre-release documentation and is subject to change in future releases. Blank topics are included as placeholders.]
Of course, you can find the latest product documentation online. For Team Foundation, which was just updated online to the final RTM documentation, see: http://msdn2.microsoft.com/en-us/library/ms181232(VS.80).aspx.