Here is an article from Forbes dealing with NFL team valuations. This is for the St. Louis Rams but you can also look at other team valuations.
http://www.forbes.com/lists/2009/30/football-values-09_St-Louis-Rams_307693.html
Go to http://www.sbrnet.com/ Sports Business Research. At the top is industry Trends. Click on football.
On the library database page http://apps.olin.wustl.edu/library/articles/db.cfm go to Plunkett's. Click on the link and once you are on the site scroll down the left hand side, and click on Sports. On the top left hand side type St. Louis Rams in the Perform search within this industry. On this site you can also find some general statistics for the National Football League.
MC
Here is an article about the Rams which lists facts about the team including revenue, owners and many other facts:
http://www.sbrnet.com/publication.asp?function=detail&magid=181311