When does the NFL matches start that lead up to the Superbowl?

Preseason Matches start at beginning of August. The NFL is currently on a 4 preseason game schedule, which is subject to change (part of the reason there may be no season in 2011). A few of the major issues with the current Collective Bargaining Agreement(CBA) talks are that of the player salaries, specifically rookie salaries, player safety issues, and health insurance for players after the current CBA expires, which is a tricky one because the owners want to expand the regular season to 18 games, from 16, to maximize their revenue. A player currently has to play for 4 seasons in the NFL to receive pension but playing 18 would extend the amount of games played in 4 years years time. Thats about all I know about that! GO BEARS!