I agree with most of the other posts... but have a few things to add:

First, grades matter, or else you'd just self-teach everything and not worry about a degree. A B+ average is not an option. Thus:

Take the minimum number of credit hours to qualify as a full time student. And demand a lot of yourself -- try to earn an A or A+ in each class you take... Read ahead, do problem sets weeks ahead of time, go to office hours. Make each class an obsession. This is much more like real (startup) life. I'd also even consider being a part time student if doing so helps you achieve this. Also, you should do some partying and have a social life, which is another benefit of not taking too many credit hours.

Pre-learn for the next semester. Read the book, do the first month's worth of problem sets, sit in on a few classes. Do some other, related reading. Do this as a reward for being ahead in all of your other classes. Doing this can give you confidence if you decide to skip a prerequisite... to see if you can handle the material.

But fun is also important, so:

Self teach. If you want to learn CS, start now. Pick up some books, start your own projects. Get nerdy. This could lead to some key independent study work with awesome faculty members. What research areas are they working on? Can you hack that? Why not stop by and talk about being a research assistant or even a work study gig?

Money:

If you need to earn any money during school, I suggest either getting a job where you can sit around studying all the time (desk clerk, etc.) or where you are being paid to contribute to research in some way, etc. The bottom line is that if you can be paid for your study hours you will prosper as a student.

Fun:

Don't feel too much pressure to engage in all the over the top social stuff, but realize that you can meet some very interesting people in college, and so be open minded to meeting all sorts of people. Friends will respect you more if you are self-possessed enough to put your academic priorities first. Besides, after two semesters of A/A+ results (see above) you will be known as someone who kicks ass. Everyone always assumes grades are the result of brains or inspiration rather than good planning and hard work (and reasonable pacing). I had a friend in college who was known for being really bright. He would help various classmates with problem sets. On several occasions the people he helped obliged him with oral sex. He's not a creep at all, but that's the sort of gratitude that being respected for your academics can lead to.

Course Selection:

Figure out which professors are well respected for teaching a particular class and make it a MUST to get in that class. Also, don't hesitate to drop a class if it's being taught badly. Most of the classes I had that turned out badly started off with a strong intuition on my part that something was a bit off, yet I persevered due to schedule constraints, etc. It's better to just drop it, add it to your pre-teaching regime (per above) and take it in the future when someone better teaches it.

College is an unexpected combination of self-teaching and guided-learning. You must always self-teach (and pre-learn) but with the guidance of an inspired prof your learning experience can be significantly more fulfilling.