Oh, one other thing. Assuming you do computer science, you will probably have some programming-heavy classes (likely with weekly program assignments), some classes that are more theory related, and a few classes that are a mix of theory and programming.
Programming assignments can be notoriously hard to time budget. Hell, I've been out of college for 10 years and I still struggle with estimating how long it will take me to do a task. I had one assignment where I ate, slept, went to classes, and all the rest of my time was spent on this assignment. For 10 days straight.
Don't take more than 2 heavy programming classes if you can at all avoid it. If you've got some other demanding classes (a hard science or math class, say), you might want to limit yourself to just 1.