Investor.Org (from the SEC)

The Securities and Exchange Commission (SEC) is aware of the limitations on their enforcement resources, so they hope this site can help the members of the public educate themselves and protect their money. The site has a laundry list of features including definitions of commonly used terms, interest and fee calculators, a background check for financial professionals, and tips on how to avoid fraud. For anyone new to investing or who might want to check out a new financial professional, this site is tremendously helpful.