General Industry Information:

http://www.healthandfitnessbiz.com/healthandfitness/index.jsp - Health and Fitness Business offers online information on suppliers and industry.

http://www.bicycleretailer.com/bicycleretailer/index.jsp - Bicycle Retailer covers bicycle industry information. 

http://www.holistic-business-journal.com/ - The Holistic Business Journal is a magazine with advice on starting and running a holistic business.

http://www.aahperd.org/aaalf/template.cfm - American Association for Active Lifestyles and Fitness. 

http://www.afaa.com/ - Aerobics and Fitness Association of America.

http://www.afpafitness.com/ - American Fitness Professionals and Associates.

http://www.aife.org/ - American Institute of Fitness Educators. 

http://www.seniorfitness.net/ - American Senior Fitness Association.

http://www.aeawave.com/ - Aquatic Exercise Association. 

http://www.nsca-lift.org/ - National Strength and Conditioning Association.

Events & Trade Shows:

http://www.healthandfitnessbiz.com/healthandfitness/index.jsp - Health + Fitness Business hosts an annual trade show.

Personal Trainers:

http://www.personaltrainerbusiness.com/ - Personal Trainer Business Forum.

http://www.aapt.net/ - American Association of Personal Trainers.

http://www.personaltrainertoday.com/ - Personal Trainer Today, industry magazine.

Youth:

http://www.ncys.org/ - National Council of Youth Sports.

http://www.americanfitness.net/ - American Fitness Alliance, focused on youth fitness.

http://www.aahperd.org/naspe/template.cfm - National Association for Sport and Physical Education.

http://www.asrbiz.com/actionsportsretailer/about_us/index.jsp - Action Sports Retailer serves the action sports and youth lifestyle industry.

Nutrition:

http://www.eatright.org/Public/ - American Dietetic Association.

http://www.nutritionbusiness.com/ - New Hope Nutrition Business Journal.

http://www.nasnutrition.com/ - National Association of Sports Nutrition.

http://www.nutritionaltherapy.com/ - Nutritional Therapy Association.

Books for Starting a Health and Fitness Business: