This is the only document you need
TFSInstall-3292010.chm from http://www.microsoft.com/downloads/details.aspx?FamilyID=2d531219-2c39-4c69-88ef-f5ae6ac18c9f&displaylang=en
you will need SQL 2008 not 2005 , Please refer to Installing prerequisites >SQL server section
Another thing to consider, will you be using Sharepoint as project portal ?, Do you have an existing sharepoint installation in your environment, or will you install WSS 3.0 during the setup on your 2003 server ?
Another thing would be , the Clients, although Visual studio 2008 SP1 is compatible with TFS 2010, you will need to install the below patch, and keep in mind there will be some functionalities not available for the TFS Administrator mainly unless Visual studio& Team explorer 2010 are installed.
http://www.microsoft.com/downloads/details.aspx?FamilyID=CF13EA45-D17B-4EDC-8E6C-6C5B208EC54D&displayLang=en
you may aslo wish to take a look at the below link for some important info and a walkthrough
http://blogs.msdn.com/b/bharry/archive/2009/04/30/tfs-2010-admin-operations-setup-improvements.aspx
Other than that the section that is most important in the installation document for you is as below, be sure not to miss the checklist
"Scenario: Installing Team Foundation Server Using Existing Infrastructure or More than One Server"
Before proceeding with the installation, make sure that windows SQL , sharepoint are most updated with regards to patches , service packs , updates ,etc..
Hope this clarifies.
