University of Florida -- Rabbits, Rabbits, Rabbits -- Great PDF resources including 4-H Cloverbud Rabbit Project Book and the series of Participant and Leader Manuals in the "What's Hoppening" series.
Rabbit Bowl "Coaching for the Coaches" -- Produced by Minnesota 4-H.
Colleges/Universities/Other
Rabbit Diseases -- Produced by Comparative Medicine Program 2002
MU College of Veterinary Medicine. Very detailed and by type and body area affected.
Outside of the US Resources
Ontario Rabbit Education Organization -- Variety of downloadable materials and activities. Fun "Rabbits Coloring and Activity book" for Primary and Juniors. (Note: this is a Canadian site.)
Rabbit Info from the UK -- lots of text but good info. University of Edinburgh produced. (Note: This is a United Kingdom Site.)
General Websites with Information
3 Bunnies Rabbit Rescue -- This is a rabbit rescue site, but it has some very good information as well.
Rabbit References Website -- tons of material from a variety of sources. Not maintained by veterinarian or other professional.