Before you ask your first AAS question...read here
I've been seeing a lot of threads from beginners asking about their 1st cycle or something along those lines.
CBB takes a more mature approach to solving your "get big" dreams.
Let us see your diet. Let us know your stats, your history with bodybuilding and anything that can help us judge how to help you.
If you're 150lbs, 6'2, training for 3 months. AAS is NOT the way to go. The hardest part of growing is your diet. Take the time to learn how to eat right, what to eat, how much to eat and how to lose fat. Once you got all those basics down and you are comfortable with them, then you should look into the more advanced stuff.
Half the time, you can get to your goals with just a proper diet and dedication. If you can't exactly say how many calories you've eaten today, then already you're being lazy and want to find a shortcut to get big. AAS may get you there but if you don't learn how to eat properly, you'll need AAS to maintain any decent size instead of just plain ol' good food. You'll lose a lot of your gains when off.