The most common type of financial aid is in the form of loans. About 75% of law students nationally borrow to attend school, usually by utilizing a financial aid package which draws from several loan sources--most need-based, some not.
All law schools require the Free Application for Federal Student Aid (FAFSA) form. The FAFSA is available at the U of U Financial Aid and Scholarships Office, 105 SSB, or online at http://www.fafsa.gov. Some schools will also require their own school-specific forms in addition to the FAFSA.
Apply early (Jan.-Feb.) in order to assure that all eligible aid is in place for your first term (common priority deadline: March 15). You do not have to wait to be accepted to a law school to initiate the process. Find out which additional form(s) your schools require and obtain them directly from the law schools. Upon acceptance a school will then be able to make your financial aid award based on this analysis report and also inform you of scholarships or grants they have available.
You may also want to investigate private scholarships offered by various organizations, parents' employers, honor societies, etc. Minority students should contact national minority organizations--see Thinking Abut Law Schools--A Minority Guide by Law Services (available from law schools or LSAC).
NOTE: Be aware that your credit rating does affect your eligibility status for some need-based financial aid. If there are any problems with your rating, clear them up now or you could be denied eligibility.
There is an excellent video on the LSAC website: http://www.lsac.org/jd/financing-law-school/paying-for-law-school.