Have you applied for financial aid (FAFSA, scholarships, etc.)? You can get quite a bit of "free money" from federal and state grants if you qualify. I was awarded something to the tune of $8,000 no strings attached money for this year, plus another $4,000 in subsidised loans (the fed pays my interest payments as long as I'm in school). There are also work study programs where you can get paid to do research, even as an undergrad, and of course there are always unsubsidised student loans.
As a grad student most places will pay you for TAing or assisting with research, I believe the ammount varies from institution to institution.