1. Let Your Major Pick You
A lot of college students ask me what majors will look best on paper when it comes time to apply for a job or to graduate school. At this point in your college education, you really have no business committing to a career yet. You should be exploring — different classes, different internships and part-time jobs, different activities, different professors. Take a wide variety of classes, even if variety is not mandated by your school's graduation requirements, and you'll figure out pretty quickly which ones you're passionate about.
2. Follow the Professors
Find out who the best teachers are and load up on those classes. The best teachers could lecture every day on the history of Brazilian trade unions and you'd still be fascinated and learn how to think. A site like RateMyProfessors.com has its limitations, but it's just one more resource to help you find the best ones. (And if you want to see that shoe on the other foot, check out RateYourStudents.Blogspot.com.) Start cultivating relationships with your professors — be engaged in class and talk to them during office hours. Don't be afraid to ask for help. Aside from the academic benefits, you'll need them for graduate school recommendations in just a few years, and sometimes they have industry contacts as well.
3. Your Job Search Starts... Now
Many professors and college administrators (including folks at the career center) haven't spent much time outside of academia, so don't treat them as your only resources as you explore careers and line up internships or other job opportunities. Make every semester and summer in college a strategic part of your post-graduation career planning — many employers make permanent offers to their interns. Gone are the days when you could get away with spending every summer in college as a camp counselor or working at the Gap. Your post-college job search starts the first day of college.
4. Be Smart About Your Financial Future
Most people borrow for college, and for every dollar you spend now, you'll be paying up to two in the future, depending on how long it takes you to pay back your loans. Check out financial planning calculators -- FinAid.org has good ones -- to figure out how much money you need to be making after graduation to make your monthly loan payments. Save your credit cards for emergencies, and don't fall for those seductive credit card pitches on campus. Get in the habit of tracking your spending (check out Mint and MoneyPants) — it's a habit that will serve you well for the rest of your life.
5. Classes Come First
If you ever have to choose between grades and extracurricular activities, save your grades. If you can swing both, then knock yourself out, but don't forget the primary reasons you're in college: your degree and your coursework. As a former graduate school admissions officer, I heard a lot of people excuse their lousy or so-so transcripts by pointing out how "well-rounded" their activities were outside of class. Instead, their transcripts just proved to me that they had misplaced their priorities. Do I even need to add that Thursday-through-Sunday drinking is even less of an excuse? (Yes, people have tried the "rich social life" story plenty of times.)
6. If You Lose Your Bearings, Take a Breather
Sometimes life gets in the way of our best intentions. You won't be able to go back and do college over again, so make sure you can give school your undivided attention while you're there. If external circumstances make that impossible (a recurring or serious illness, grave family difficulties, needing to work more than 20 hours per week), explore taking a semester or even a year off to get a handle on whatever that problem is. Most students in these situations try to push through the crisis, and their transcripts end up looking like train wrecks. They'll have to explain and make excuses for their grades for a long time to come. You're much better off showing people a transcript with great grades and having to explain why you needed to take time out in the middle.