I cannot stress enough how "perfect" you have to be. I think Milkman tried but I don't want you to miss the point.
You will need to APPLY to get into OCS (Officer School) you can enlist in the military and most branches will take you as you are. However, to become and officer the tables are turned a little... here the military has a chance to be picky. Of all of the services the Air Force is most likely the choosiest.
After you get into OCS (you can do it, I'm not trying to discourage you, but I don't want you to think you can slack and get there either)... anyways, after you get into OCS you will need to apply to go to flight school and again, the Air Force can afford to be picky. Everyone wants to be a pilot. The competition is stiff and they will gather references from everyone you can think of and they will interview these references (so don't bother lying). They are going to want to see extensive volunteer work, excellent to near perfect grades, a completely clean criminal record (a parking ticket can throw you off - so drive like someone's grandpa just to play it safe). On top of all of this you will have to interview well, look respectable, be in better shape than anyone you know, and be able to write essays in an intelligent manner.
Start working on your references now... shoot for the most respected, highest ranking people in society you can think of. Senators, State Reps, Governors, Mayors, Chief of Police, Deans of Colleges, Any one heading any type of volunteer program, City Council Members, Judges, etc. Meet these people, write to them, get to know them and make sure they get to know you.
I know all of this may seem hard or damn near impossible. The truth is: It's going to be the most difficult thing you will ever do, but it is far from impossible. You CAN do this, it will take dedication, but I promise you, you can do this.
I'm not trying to discourage you by telling you all of this. These are things I wish someone explained to me when I was 16 (or 15 even). I come from a military family (both sides) and was unable to serve due to my stupidity as a youth (I did some stupid stunts and blew out my knee the surgery helped but the damage was extensive enough that it took 3 years for the knee to completely heal... yes, three YEARS. Even now, at 28, I still walk with a limp at times). If this is your dream, go for it and don't stop not for a second. You are young enough that you can still own the world if you really want... NEVER LOOK BACK.
Remember: Anything really worth doing is not only worth doing right but is also hard as hell! 