Lot of good advice here. There are some things to realize.
1st; while there are only about 100-150 who will get an LOA, there's also a select few that will actually get appointment in the next couple of weeks. There were quite a few in the class of 2011 and 2012 to have actual appointments.
2nd; The most important thing to realize is that EVERYONE who makes it to the air force academy and accepts it was an exceptional and outstanding student/kid/athlete/etc... in school. Definitely be excited, but realize that when you walk into arnold hall on inprocessing day, that you AREN'T any more special than anyone else walking in that door. Those standing next to you ALSO had 3.8-4.0 gpa's; 2000+ SAT, etc... They were all state athletes and so on. The biggest mistake many new cadets make is making TOO MUCH of "Military related" high school activities. Trust me when I say; No one wants to hear that you did JrROTC or Civil Air Patrol. Basically; remain humble. You have been accepted to an IVY LEAGUE school. Be excited, but realize that if this was Harvard or Yale, every other person going there is ALSO exceptional just like you.
3rd; Finally, realize and trust me when I say that LIFE IS SHORT!!! There isn't one person on the planet that can guarantee tomorrow for you. As such, don't wrap yourself in "Bubble Wrap" or even have that mentality. Going to the Air Force Academy should NOT BE YOUR GOAL IN LIFE. The academy should be a MEANS of reaching and fulfilling your goals in life. That doesn't mean be stupid and do stupid things that will push your luck at getting hurt or getting in trouble. It mean; ENJOY YOUR LIFE. Enjoy your senior year. You WILL MISS IT. Do ALL the things you can. Do all the things you never thought you would like. Go to homecoming. Go to the prom. If you don't have a girl friend or boy friend, this is the PERFECT opportunity to invite that really nice, funny, and popular girl/boy that NOBODY ever asks to go to a dance. Don't worry what others might think. YOU ARE GOING TO THE AIR FORCE ACADEMY!!!! SCREW THEM!!! Be the great, excellent, fantastic person that everyone knows and what got you accepted. Go to EVERY school function that is left for the year. Sporting events. School plays.
Keep a nice "$h*t Eating" GRIN on your face. Be excited. Solidify all your existing friendships. Make friends with the rest of your class. At least just remain positive, polite, considerate, friendly, etc... with everyone you meet at school. Remember; be humble. There are a lot of your classmates who will not even be going to college or junior college. Many will be working at the "Mini-Mart", Kmart, lawn service, etc... Appreciate the opportunity you have in front of you. It is something that NO ONE can even imagine unless they've been there. Not even parents, brothers, sisters, husbands, wives, etc... They may understand some, but not really what you've been given. Even you won't be able to appreciate it all until later on when you look back in retrospect. Most of all; make the best out of your senior year in high school. And I wasn't kidding about asking that girl or guy to homecoming, Sadie Hawkins, Prom, etc... Imagine SHARING your excitement of your senior year with someone else who can ALSO have a great finish to THEIR senior year. Trust me; GOOD FORTUNE tastes so much better when you can SHARE it. Have a great senior year. God bless you and thanks to all those who have applied and are willing to serve our great country. later.... mike....