-- Don't make a lot of new credit requests: Every time you sign up for a new card or new credit account, your credit score is updated. If you're thinking of a big loan, like a mortgage, don't open new accounts in the months leading up to it. Credit requests account for 10 percent of your credit score.
-- Use installment and revolving debt: The mix of credit also impacts your score, with credit cards (revolving debt) having more weight than car loans and mortgages (installment debt). This final component accounts for 10 percent of your credit score.
Once you start using credit, you'll want to stay on top of your credit score, which is also easy (and free). The three main credit-reporting agencies are Experian, Equifax and TransUnion; each is required to give you a free copy of your credit report once every 12 months (go to www.annualcreditreport.com for instructions). You can see how your credit history is progressing and -- very important! -- catch mistakes before an important credit decision is made.
A good credit score is important; it can save you very real money in interest charges and, occasionally, can spell the difference between getting credit or not. But just as important is learning to use credit effectively. That's a topic for another day, but in general, try to live within your means and use credit sparingly! Good luck.