What exercise regime should a 17 year old guy have to get fit?

I want to build lean muscle, not bulky muscle. I am a 22 year old man, am 6 feet tall, 250 pounds - strong but need to lose a few pounds around the gut - I do heavy wei... I am going to start using P90X in hopes of gaining muscle mass and looking similar to the people on the infomercials. What are some good workouts to build overall body muscle, i don't have much time on my hands to to train each individual part, so i need something tha... However, I'm not sure what muscle groups I should be working out together and on what d... I was impressed with the results but feel that I'd lost a lot of muscle size.