I go to a lot of sites online for information pertaining to finance, but this is one of my favorites. Bionic Turtle has great forums, great instructional videos, get explanations, just great everything. If you are interested in the FRM, CFA, CAIA, etc, you simply must go here.
David Harper runs the site and has made it into a cornucopia of finance knowledge. If you want to brush up your finance skills, this and investopedia should be your main stops. I encourage you all to check the site out, book mark it, visit daily. I do.