Are you looking to buy a house, a car or other major item using credit? You will almost certainly hear about your "credit score," if you are.  It's not something you can study for, though you can improve it: Here are the 7 things you need to know about getting and keeping a good credit score.

1. Pay your bills on time. This is the number one most important factor in determining your credit score. Start making timely payments and you’ll improve your score within months. 
2. Don’t use all the credit available to you. Lenders look at your “usage ratio”—how much debt you owe compared to the total amount you could borrow. The people with the best scores tend to use less than 10 percent of their available credit. Also, despite the urban legend to the contrary: there’s no advantage to carrying a balance from month-to-month. You need to use your card or they may close down the account but you don’t need to carry a balance. 
3. Time your applications for loans. Applying for new credit can hurt your score. The best way to protect yourself is to time your applications—whether for a car loan or a mortgage—into the same 45-day period so they’ll count as a single inquiry.
4. Before you start shopping for loans, check your credit reports. Get free copies of all three of your credit reports at www.annualcreditreport.com. By law, you’re entitled to one free report from each  bureau per year; check a different one every four months to keep an eagle eye on your score. You can get a free estimate of your score at creditkarma.com or at credit.com. If you’re planning to get a loan in the near future, best to go to www.myfico.com and pay $15.95 for an official FICO score.
5. Scan your report for mistakes. According to a study by US PIRG, 25% of all credit reports contain an error big enough to get someone denied a loan or credit card, and 79% contain a cosmetic error like a misspelling or outdated data. Once you’ve gotten your free credit reports (see #4 above), check for errors: Are there credit card you don’t recognize, addresses where you’ve never lived, delinquencies you’ve never made? Have the bureaus combined your information with that of someone with a similar name? 
6. Report errors asap to the appropriate credit bureau. It has 30 days to investigate and respond. In one month, your report will update automatically. 
7. Improve your credit score before you apply for a loan. The difference between having a good score and a lousy score could save you tens of thousands of dollars in loan payments. Keep making those on-time payments and wait until your score improves before signing up for a major loan. You can estimate how good financial behavior will improve your score here:http://www.bankrate.com/calculators/credit-score-fico-calculator.aspx