Your main amount of financial aid is reported to you via the school. As Einstein said, you fill out the FAFSA form and using that, the university(ies) you've been accepted into will send you a financial aid letter detailing the scholarships, loans, grants, etc. you're eligible for.
Other, smaller financial aid money can come from scholarships you apply to individually. They're usually around the $1000-$2000 amount and you usually have to write an essay or something when applying. Not as large as your government subsidized loans, but not bad nevertheless.