Search for government programs that offer special job opportunities for graduate students to help them pay for school. One of these, USA Jobs, helps students find jobs based on their area of interest, location and financial needs.
Contact your graduate program department about teaching assistantships or on-campus jobs. These opportunities can provide experience that will help you build your resume and help chip away at graduate school costs. These programs may also be able to advise you on scholarship opportunities.
Seek paid internships that will give you school credit and income at the same time. Many graduate schools require an internship component that will send you out in the community to explore your graduate field, and these internships may or may not be paid. Paid internships let you gain experience in your field and ensure you won't be in too much debt when you finally enter the field.