The Cat Fanciers' Association (CFA)
http://cfa.org

Winn Feline Health
http://www.winnfelinehealth.org/

The Maine Coon Heritage Site
http://pawpeds.com/MCO/mchs/

The Merck Online Veterinary Manual
http://www.merckvetmanual.com/mvm/index.jsp

Cat Scratching Solutions and how to trim your cats nails.
http://www.catscratching.com/