1.) No matter how much advice I give, you will have to find all this out for yourself, because that is just how it works.
2.) College is actually not scary and you are more prepared than you think.
3.) You will NOT have a 4.0 GPA unless your major is Floral Design, etc. Oh and never think a grade is that important to your life (this I recall my 3rd grade teacher saying).
4.) Make sure you think before you do something, but don't be afraid to not try something out.
5.) MEET YOUR PROFESSORS. If they know who you are and they know you work hard they are nice to you in return if say you have a seizure or swine flu.
6.) While the idea sounds cool: avoid suites as dorms.
7.) You need to learn to do laundry (really it isn't that hard, although half my suite didn't know how to properly load a dishwasher so...).
8.) If you lose contact with someone, it is likely forever. My condolences. On the bright side you will begin to meet lifelong friends in college, but don't expect friends to just pop up all at once.
9.) As Alex said, you change. Don't prevent it, embrace it, unless you change like my roommate from nerd to alcoholic. Oh and don't force yourself to change either.
10.) Alex lied about saying everyone gains weight in college. (It's mostly just women).
11.) On the flip side, weekly parties with beer will have that effect.
12.) Have fun, be safe, and don't do anything stupid.