do you have current copies of your credit reports and have you verified all accounts are yours?
start there then see what you have in collections, it you have past dues in collection those need to be paid.
Do you have an auto loan?
Credit cards?
I hear the B of A does a secured card they will report to the credit agencies. You need to have some positve tradelines in order to improve your scores.
Also reducing the balances reported is said to help. So if all you owe is your student loans you need to try to pay that down quicker to show a smaller balance.
read some of the threads at the top of the pages in the different section and you will frin generous amounts of information to help you.