Below are the online resources that I rely on the most:

ADDItude Magazine

ADDitude delivers expert advice and caring support to parents and adults living with attention-deficit disorder, and for professionals working in the field. They provide great resources through their website and email newsletters, downloadable articles and e-books, email newsletters, webinars, and their print magazine.

ADD.org

The Attention Deficit Disorder Association's website has a wealth of information, and they host regular webinars than can be quite useful.  They also co-host the annual conference on ADHD with CHADD.

CHADD.com

Children and Adults with Attention-Deficit/Hyperactivity Disorder (CHADD), is a national non-profit that provides education, advocacy and support for individuals with ADHD. In addition to their website, CHADD also publishes Attention magazine and Attention weekly, a free email newsletter.

YouTube Channels

For some people with ADHD watching videos is so much easier than reading. Here are a few YouTube channels that I’ve found helpful - in in some cases enjoyable!

Dr. Charles Parker

Dr Charles Parker is a psychiatrist and neuroscientist and author of "New ADHD Medication Rules" who has produced scores of videos on ADHD and brain science.  I've learned a lot from his videos, especially regarding the "therapeutic window" for medication effectiveness.  His playlist "9 'ADHD' Diagnostic Insights" is a good place to start.  He also has his own website with links to other materials. Disclaimer:  Be sure to use your own judgement and consult your own doctor.  I don't buy into some of the claims Dr Parker makes, like brain scans, "leaky gut", and some supplements, but he may well be right!
 

How to ADHD - Jessica McCabe

I first became aware of Jessica McCabe through her TED talk “This is what it’s really like to live with ADHD.” She has designed her YouTube channel as her ADHD toolbox -- a place to keep all the strategies she’s learned about having and living with ADHD. She takes a funny, positive, lighthearted approach.

ADD Crusher

I enjoy ADHD Crusher’s clips with short and to the point graphical videos. I especially like his Tips For Staying Focused And On Track where he advocates using a “BS, that’s not what I’m doing right now” label for distractions.

Totally ADD

Comedian Rick Green’s Totally ADD takes a fun and sometimes silly approach to ADHD education. He’s known for his documentary “ADD and Loving it?!”