Which workout plan is best for me? (Guy)?

I am 16 and i weigh about 130 pounds. I am fairly skinny. I am looking for a workout/fitness plan to gain a couple pounds of muscle but i want to look more lean and defined rather than bulky and buff. I don't want a lot of muscle but i want what i do have to be sharp and tone. I have been looking into P90X because it sounds like more of a refining product rather than a bodybuilding or weight lifting. Any ideas?