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Start building credit early - even before college starts, if you plan on taking out college loans. Ask your parents to sign over a bill that you pay on time each month. Get a credit card with a low limit and a bank account that you balance each month. Avoid opening several charge cards at once - not only will they be hard to repay, but having several new accounts when you have a short credit history will actually cause your credit rating to drop. Get a part-time job.
Each of these things can help you establish good credit, high in turn can help you get a good student loan rate. More importantly, establishing credit early will help ensure that you have a long (and good) credit history by the time you graduate from college, which will help you with all your important, large post-graduation expenses.