There isn't any one site that shows OS then SQL version. The link below is for SQL 2008, and then just to the right at the top of the article you can change to older versions of SQL.
As for SQL 2008, scroll to the bottom of the article and it will list each version of SQL 2008 and what OS it can run on.
http://msdn.microsoft.com/en-us/library/ms143506.aspx
Chris Powell
George: You're kidding.
Elroy: Nope.
George: Then lie to me and say you're kidding.