I will start with the ones I listed for the Clarkson Social in Rochester... Note that all of these are pretty much aimed at engineering students (might change for other majors).
1. (Ok this is for pre-prefrosh) PAY Attention in your chemistry and physics and calc classes in high school!!! It will make your life 10 times easier when you get to college! (I know... I had to spend so much more time studying in college because I didnt pay attention to calc and physics the first time!)
2. DO NOT blow off your freshman classes because you have already taken them (ie the calc, chem & physics I mentioned above!) It will be similar material, but the tests are MUCH harder... they actually expect you to think!! not just repeat repeat repeat! I know many of my friends that were really smart, ended up graduating with 2.5-2.9 GPA's because they thought freshman year just didnt matter, and they would do better in their "real" classes... guess what? All of your classes count!! Take advantage of the "easy" ones!
3. Get a co-op or internship while you are in college!! Im a key recruiter at Harris, and I cant tell you how many times we have turned down kids with great GPA's or good leadership because they just dont have industry experience, or didnt seem to have the drive to get a "real job" while in college.
4. Don't be afraid to ask for help. I dont know if all schools are this way, but Clarkson was great at giving help IF you asked... your advisor will meet with you occassionally, but most schools expect you to act like an adult and ask for help if you need it. Dont be embarrassed... I was a physics tutor, and had to go get tutored in calc 3, it was really hard to accept at first (I always thought I was smart!) but I got a lot from the tutor, and ended up with a B+ instead of the D I got on my first test!!
5. At any decent engineering school, you WILL fail one of your first tests. At Clarkson, its physics... everyone fails the physics test! Studying in college is so much different from studying in high school. Learn what works for you, find some friends, get a tutor, or just plug through it.
And some other advice I would give:
6. Get a credit card... I came out of college and had ZERO credit... with money in the bank, I wasnt allowed to finance a $1700 bed, but my boyfriend, in 60k of debt could! Your debt and/or a credit card will get you some credit to start with. But keep your credit on the good side. If you have to, use it to pay for things like books you already have $$ for, and then send it home with your parents and dont touch it until next semester!!
7. LEARN TIME MANAGEMENT!!! We had A LOT of fun up at Clarkson, but we also worked really hard. I can remember during pre exam weeks (dubbed he** week), I would plan out every waking hour of my day, 2 hours on physics, 3 hours on chem, 2 hours for lunch, 5 hours on calc, 1 hour for coffee, 3 hours for physics, 2 hours for frisbee... etc. You dont have to go to that detail, but dont procrastinate, start assignments the night they are given to you, first thing in the semester, or you will end up behind for the whole semester. Figure out when you are going to work, and when you are going to play and commit yourself to it!
8. This is important, and I know it may cross some small lines, but its what my dad told me, and I think its the best advice I ever got. We know you are going to party. BE SMART about it... seriously, cabs or walking in the cold are worth it when lives are at stake, even just one is too many. Also, if you are going to party, always bring a friend that you know will watch out for you, and do the same for your friends (especially girls). Dont just run out with the new person you met and head to their friends party... take a friend you know and trust, it will be worth it!!
Ok ok thats it

best of luck in college!! It WILL be the best time of your life!