USA Cycling and NORBA are the main sanctioning bodies for bicycle racing in the US .
www.usacycling.org

The Hawaii Bicycling League website has maps and articles as well as excellent local information.
http://www.hbl.org

DH Hawaii is a local site with lots of pics and community projects.
http://www.dhhawaii.com

Why walk when you can roll, BIKEFACTORY Sportshop.
http://www.bikefactoryhawaii.com

Not just any shop, The Bike Shop
http://www.bikeshophawaii.com/Index.htm

While on the North Shore check out Barnfield’s Raging Isle
http://www.ragingisle.com

Tours with experienced and qualified guides, contact Bike Hawaii.
http://www.bikehawaii.com