The National Check Fraud Center – Everything you ever wanted to know about check fraud and more. A bit outdated but lots of statistics and research links.
www.ckfraud.org

Financial Crimes Enforcement Network – A great site for U.S. Companies with global operations that rely heavily on electronic cash management.
www.fincen.gov

American Bankers Association
www.aba.com

Bank Administration Institute
www.bai.org

National Automated Clearinghouse Association
www.nacha.org

Uniform Commercial Codes 3, 4 and 4A – An in depth and comprehensive breakdown of these codes from the Cornell University Law Library
http://www.law.cornell.edu/ucc/3/overview.html
http://www.law.cornell.edu/ucc/4/overview.html
http://www.law.cornell.edu/ucc/4A/overview.html

Banking Industry Legal Resources and Overview – Via the Cornell University Law Library
www.law.cornell.edu/topics/banking.html