Diet makes all the diff. in the world. When i'm bulking i notice a big diff. just from adding 1 gallon of milk every day. Also eat lots of protien(eggs, chicken, lean beef, fish, cottage cheese, etc.), carbs, and leafy green veggis. DOn't forget essential fats(nuts, omega 3's, etc.)
Don't overtrain. Rest. U'll grow.
Also, remeber as u grow u have to keep increasing calories to keep gaining.