I don't know where you live, but if you live in the United States, then use FAFSA. You submit your tax records and it calculates how much financial aid you are eligible for. Just remember that you need to do a FAFSA every year you are in college to renew your financial aid. Find out more at http://www.fafsa.ed.gov/.
There is also the CSS and it's from CollegeBoard (the people who make AP tests and SATs). You can find out more here http://student.collegeboard.org/css-financial-aid-profile.