Bicycle Helmet Safety Institute: Information on bicycle helmets, standards, and cycling laws; the helmet advocacy program of the Washington (DC) Area Bicyclist Association.
Bicycle Law.com: Legal advice for injured cyclists hurt in traffic accidents or by defective cycling products. Founder Bob Mionske is a cyclist and attorney, and a two time Olympian and former US National Champion.
BicycleSafe.com: An illustrated guide to bicycle safety, including an illustrated guide to how to not get hit by cars.
Bicycling articles by John Allen (& guests): Articles on bicycle safety from an expert.
Bicycling Life's Safety Advice Page: A large site that covers vehicular cycling concepts, including riding and maintenance tips.
Bicycling Street Smarts: A compact tutorial on how to ride a bicycle in mixed traffic.
Bicycling: Commuting, Touring, Camping, and Safety: Commuting and safety tips.
BikeForums.net Advocacy and Safety Forum: Topics include helmet safety, children's bicycles, and bicycle advocacy.
Chainguard: Vehicular cycling email discussion group.
Commuting and Road Safety: A forum to chat about commuting and road safety.
eMedicine Health - Bicycle Safety: Consumer health resource center providing bicycle safety information.
First Aid for Injured Mountain Bikers: Descriptions and photos of typical mountain bike injuries, with immediate care, assessment, and treatment.
Hampshire Cycle Training: Hampshire Cycle Training provides cycle proficiency courses throughout Hampshire for children, adults, schools and businesses using nationally qualified instructors.
John Forester's home page: Vehicular cycling information from a pioneer in the field.
MassBike Bike Laws and Legislation: Links to the bicycle laws for US states and beyond.
Melbourne Magpies - Watch Out Cyclists!: Provides details of local locations for cyclists to avoid.
National Bicycle Safety Network: An American coalition of public and private organizations and agencies working together to increase safe bicycle use. Great resource for safety issues, especially traumatic head injury reduction.
Palmetto Cycling Coalition: A non-profit organization dedicated to making South Carolina safe for all cyclists.
ProBicycle: On-road bicycling advocacy.
Safe Cycling Lessons: Safe cycling tips from the Lawrence Livermore Lab in California (note - applies to U.S. road law).
Seidler Productions: Traffic education for kids, public service announcements, links and bicycle safety products.