caddac.ca - The Centre for ADD/ADHD Advocacy in Canada hosts a very complete list of resources and information for those living in Canada.
ADDcoach4u.com - Coach Pete Quily has amassed a large database of information. Particularly of interest - his information on international support groups and resources and his blog posts on the positives of ADHD.
ADDISS - U.K. - The National Attention Deficit Disorder Information and Support Service. We provide people-friendly information and resources about ADHD to anyone who needs assistance - parents, sufferers, teachers or health professionals. Whatever you're looking for in ADHD, we'll do our best to help. 020 8952 2800
ADHD Europe - To advance the rights of, and advocate on every level throughout Europe for people affected by AD/HD and co-morbid conditions in order to help them reach their full potential.