This is just a sampling. Most of the sites have their own links to extensive additional info as well.
Dysautonomia Information Network http://www.dinet.org
National Dysautonomia Research Foundation http://www.ndrf.org
Dysautonomia Youth Network of America http://www.dynakids.org
National Institute of Health (on Dysautonomia) http://www.ninds.nih.gov/disorders/dysautonomia/dysautonomia.htm
Mayo Clinic (on Autonomic Neuropathy) http://www.mayoclinic.com/health/autonomic-neuropathy/DS00544/DSECTION=1
Vanderbilt Autonomic Dysfunction Center http://www.mc.vanderbilt.edu/root/vumc.php?site=adc
American Association of Sleep Disorders (on Sleep Apnea) http://www.sleepapnea.org/info/index.html
American Urological Association (on Neurogenic Bladder) http://www.urologyhealth.org/adult/index.cfm?cat=03&topic=109
United Mitochondrial Disease Foundation http://www.umdf.org (not a certain diagnosis for me at this point but something that has been suggested & corresponds with some testing I've had)
The Oley Foundation - support & information organization for those on long-term HPEN (total parenteral or enteral nutrition, aka IV nutrition or tube feeding) http://www.oley.org
The Spoon Theory - an EXCELLENT read regarding the reality of living with chronic illness (written by a young woman with Lupus) http://www.butyoudontlooksick.com/2006/02/the_spoon_theory.php#more
National Chronic Invisible Illness Awareness Week http://www.invisibleillness.com
Rest Ministries http://restministries.org
Syracuse Crew - see what the "little" brother Tim is up to http://www.suathletics.com/index.asp?path=crew&tab=mens
Independent Lens - a great film series on PBS http://www.pbs.org/independentlens/
Beautiful Lengths - a program (sponsored by Pantene) that collects hair donations (at least 8") to make wigs for those who need them http://www.pantene.com/en_US/beautifullengths/index.jsp
Johns Hopkins University, my alma mater http://www.jhu.edu
National Public Radio http://www.npr.org