If you are trying to build a credit score from a damaged profile, one of the best ways to establish and show credit responsibility is to use a secured credit card to do so. Good credit card companies will report payment history to the three major credit repositories which will help to raise credit scores if you use the card instead of a debit card or cash, pay the balance down to 0 each period (just as you would with cash), elect to raise credit limits over time, but continue to maintain a 0 balance that goes beyond 30 days. This will result in having open credit funds available at all time, but not being used which helps credit scores.
Bankrate has done a great job of showing who some of the best of the best secured credit cards are. Follow the link to find the one that's right for you.