What are your physical stats? What is your diet like? How much are you lifting? What is your workout plan? You're young, so your body is still going to be doing a lot of growing over the next few years. Diet is the #1 thing you can do to put on size/strength...that goes for anyone. EAT. You will put on at least a pound or two a week doing that. I read your other post on what supplements would be best for you. And what everyone mentioned is really all you need. I put on +30lbs on my bench in two months taking whey protein, multivitamins, fish oil, and eating decently.

You asked what else you can take to help maximize your gains. Diet and the supplements that I mentioned + your own hard/smart work make up about 98% of any possible gains. There's not much else that's really worth the money that is going to help very much.