U.S. Federal Deposit Insurance Corporation (FDIC) - insures deposits and promotes safe and sound banking practices. Has a bank database that allows users to check banks' status as insured depository institutions, their financial condition and their condition relative to other institutions.
Legal Information Institute: Banking - overview of the subject, with links to federal, state, and other materials on U.S. banking law. From Cornell University.
Bank Administration Institute - professional organization devoted to improving the competitive position of financial services companies through education and research.