Two main pieces of advice:
1- DO NOT PICK YOUR ROOMMATE ON FACEBOOK. I did that. It was a mistake. We got along great the first 2 months of school and then after that things went south pretty quickly. She became really withdrawn from our original group of friends, now to the point that I don't talk to her at all if I can help it. Luckily I live in a dorm that is suite-style and my two best friends here live next door and across the hall, so I still love where I live. I can't wait to live on this same floor again next year, but I'll be living with one of my best friends and we will share a suite with two of our other good friends.
2- COLLEGE IS ALL ABOUT PERSONAL RESPONSIBILITY. Seriously, if you cannot exercise personal responsibility, than you are not mature enough to be in college. You are responsible for getting your work done, managing your money, getting to class, meeting with professors if you need to, being responsible with partying, etc. College is a LOT of independence, and it's great.... but you just need to be responsible and accountable for your decisions.