You can get the Free Application for Federal Student Aid (FAFSA):
If you're going to file electronically at fafsa.ed.gov, start looking at the website in December and sign-up for your PIN number. Then you'll be ready to enter the information in January.
The FAFSA will list deadlines for federal and state aid. Also check the requirements at the colleges your child is interested in applying to. Some require additional financial aid forms.