Questions 83-94 on the FAFSA allow you to send the info on it to 6 schools. You need to find out the federal school code and financial aid office addresses for all the school you could attend. It is okay to send schools that you are wait-listed at, going to be interviewed at, ones you have been accepted to, and any others you have space for. It will not hurt your financial aid package that you will get from the school you chose to attend. You can call any of the financial aid offices to confirm this if you want to, though I think that this is right.
Do it now and file your taxes asap as well, if you have not yet.
g-luck getting some $$$.