From Joel On Software:
Without further ado, then, here are Joel's Seven Pieces of Free Advice for Computer Science College Students (worth what you paid for them):
1. Learn how to write before graduating.
2. Learn C before graduating.
3. Learn microeconomics before graduating.
4. Don't blow off non-CS classes just because they're boring.
5. Take programming-intensive courses.
6. Stop worrying about all the jobs going to India.
7. No matter what you do, get a good summer internship.
Now for the explanations, unless you're gullible enough to do all that stuff just because I tell you to, in which case add: 8. Seek professional help for that self-esteem thing.
Read the whole thing here.