Help me Help them

I'm helping a buddy of mine lose weight, he's around 285-290 right now and he wants to get down in the 250 range. This is my first time ever actually trying to "coach" someone into losing weight and toning down. So far I've decided that for the first three months he won't even see the weight room, it'll be strictly cardio and bodyweight excersizes. I guess my real question is what type of workouts will work the best, I have a strong football background so i'll be incorporating alot of agilities and sprinting type of excersizes, but I could use some help with bodyweight excersizes.
 
P.S. Any ideas on dieting too would be helpful.
 
thanks