BeeSource Every beekeeper needs to know about this website. You can find discussions on just about any beekeeping topic, good plans for building hives and related paraphernalia, and all kinds of useful information.
Beekeeping Naturally Michael Bush is a legend in the beekeeping world, has published several great books and maintains a website to share his wealth of knowledge.
International Beekeeping Forums Similar to BeeSource but with more international contributors.
The National Honey Board You guessed it, all about honey. Great recipes as well.
The Hive and the Honey Bee Cornell University Beekeeping Collection. One of the largest and most complete apiculture libraries in the world.
Eastern Apicultural Society of North America, Inc. (EAS) - an international nonprofit educational organization founded in 1955 for the promotion of bee culture, education of beekeepers, certification of Master Beekeepers and excellence in bee research.
Master Beekeeper George Imirie (1933-2007) of Maryland published scores of helpful essays for beekeepers. They can be found at http://pinkpages.chrisbacherconsulting.com/
Beekeeping - Apiculture in Arkansas - by the University of Arkansas Division of Agriculture
Warre Hive, natural beekeeping?