If you're looking for a quick way to "sandbox" Team System and Team Foundation Server, you can download a fully-configured VPC image from the MSDN Subscribers download area.

Login to your MSDN Subscribers area.  Go to downloads.  Expand the tree to:
Developer Tools->Visual Studio 2005->English->Visual Studio 2005 Team Suite Trial Edition (For Evaluation Only)
Get the downloads for:
 Visual Studio 2005 Team System VPC – Part 1 of 2 (English)
 Visual Studio 2005 Team System VPC – Part 2 of 2 (English)

That will give you a full Virtual PC image with TFS already installed and configured, and the Team Suite edition of Team System installed.