Before you begin shopping for a house, get a copy of your credit report. Your credit score will play a large part in determining the interest rate you are able to get on your loan. The FICO credit score is the most widely used and ranges from 300 to 850 [source: Bankrate Credit].
Credit scores are affected by such things as the number of credit cards you have, outstanding balances, student and car loans and whether you pay your bills on time. The higher your credit score, the more likely you'll be able to get a loan to buy a house at a lower interest rate.
It is not unusual for there to be mistakes on a credit report -- often mistakes that bring your credit score down. Review it carefully and correct any mistakes you find before you apply for a home loan.