Fill out the Free Application for Federal Student Aid at Fafsa.ed.gov. You'll submit this form along with your college applications, and it will help to determine how much aid you can get based on the college's tuition and fees. This will offer you a combination of grants and loans.
Compare your offers of federal aid to determine how much extra money you need to pay for school. Federal financial aid will have the lowest interest rates and the most generous payback plans, so you want to take as many of these loans as possible. You'll then know how much more money you need to pay for your school. In many cases, a combination of school and federal financial aid, along with work-study will be enough to cover the cost.
Apply for a private loan from banks. Many lending institutions offer private loans to students and while not all banks will offer loans to people with bad credit and no co-signer, there are some that will. You should expect to pay higher interest rates than those with good credit, however. FinAid has a list of possible lenders for private loans.
Talk to your school about opportunity loans. Some lenders give schools money that the school can then loan to students with good grades but bad credit. Your school's financial aid office will be able to help you determine if you qualify.