I asked this question here when i first started with a bow a couple years ago. Everyone said to go to a respectable dealer and its very true. There are so many things to take into consideration its impossible just to buy one off craiglist. I actually took lessons from a pro who lives near me (who also happened to be a game warden ha ha! ) and that was very helpful too.

Not knowing how much you've grow already and your size stature I would recommend a bow with a draw adjustment from 23-30" and poundage under 50. Diamond has a great starter/mid grade called the RazorEdge that adjusts from 30# to 60# with draw lengths from 19" all the way to 30". Nice shooting bow too @ around $330 for everything except arrows included. Martin has a simular draw length/weight range as does PSE . With the bows of today and the available draw modules and insert cams you don't have to settle for a cheap bow to get started. Start under 40# and learn to shoot, then step up until you are able to hold,sight and shoot well enough in poundage. "DON'T" go to a box store for your purchase, go to a Pro Shop and have them set you up right hte first time and save time ,money and frustration with dealing with somebody who knows little or nothing about shooting a bow.Correct draw length is more important then draw weight at this time. Get fitted right

Find a quality mid-range bow that offers a lot of flexibility in its draw length. Like previously stated, at your age you will be need to be adjusting your bow continuously to match your changing draw length. Also look for bows that can adjust the draw weight to 50 lbs. Keep the weight low at first until you have mastered the proper form and have gained confidence. 50 lbs is quite capable of killing a deer and there is no need to rush it. You should be able to find a quality bow for under $500 that will offer these aspects. Check your local bow shops and talk to the guys there about shooting lessons. Most are happy to help especially with young newcomers. Good luck and welcome to the brotherhood.