Unfortunately, college isn't free, and, more unfortunately, the process of paying for college isn't easy. These resources can help.
FAFSA is the federal government's student aid application. Beyond federal need, states use FAFSA data, and many colleges use the same data to determine merit aid and other scholarships, so it is important to complete the FAFSA even if you don't qualify for federal aid.
Note that the federal government uses income data from what they call the year "prior prior" - this is the calendar year of the student's spring sophomore/fall junior year. It can be helpful to prepare your family for this year in order not to make any common mistakes during this time.
Preparing for Prior Prior Year Edvisors
EFC estimator Saving for College - useful for getting an idea of what your aid might be before applying
EFC estimator Big Future
FAFSA On the Web Worksheet for Families - Paper version to complete before completing online
Once you are accepted to the colleges of your choice, you will get a financial aid report (or "award letter") which will help you understand how to pay for college. You can choose to follow the suggestions or not; these are available to help you see how paying for the particular school might be possible. At this time, you'll want to think about things like whether you want to take on debt and how much to take on.
Big Future: Compare Your Aid Awards (calculator)
College Cost Calculator (After Award)
Loan Repayment Plans
Standard - higher payments but quicker payoff, less interest
Extended - lower payments over a longer period of time
Graduated - low income that should increase over time