I agree with what RedZone said. Plus, most schools require, in addition to the FAFSA, the Need Access form which, even if you can fill it out now (and I don't think you can), there is a charge per school.
So, while I'm VERY in need of Fin Aid, I'm not considering doing it until late January, when I can do it all and when hopefully I've heard something good from at least one school, or somethings bad from some schools so I know not to do a Need Access form for them.