Things to watch out for? I would point to being involved. Stay in constant contact with your son and ensure he understands that you are "there" for him no matter what. He will face dilemmas at times, whether school or personally based, and he will be making the decision daily whether to rely on his own judgment or to call you. Also, I hate to admit this, but at my school we got away with a LOT of things that we could not have done at home. We sometimes ran around at night, brought boys into the dorm, watched TV shows we probably shouldn't have, etc. Ugh. Looking back I can't believe we did all of that and yet 100% of my class went on to graduate from college!
Anyway, I just think that it's truly important that you minimize the impact of the distance b/w yourself and your son. Good luck!

There is no one best place for teens; some are simply more appropriate for your child than others. In any case, parents should not make an enrollment decision without thoroughly checking out at least three separate quality schools or programs to make sure they are not just selecting the first place that sounds feasible or has worked before for another child.