it all depends on what position your looking at.
for lineman...nothing specail: squats, leg press, deads, clean and press, bench and a lil bit of hamstrings too. all those and alot of them.
for line backers and fullbacks and other power players you have that arent in the trench: squats, leg press, clean and press, becnh, seated calf raises, lying hamstring curls, sitting hamstring curls.
all of your speed players: squats michael vick style( low weight amount, and jump at the top of the motion), seated rows, military press, bench, tons of calf and hamstring work.
and tons of food for all that running you should have your playters doing.