I seem to end up referring people to the same places to have online discussions over and over again, so I wanted to share them here. Online forums can be a great way to talk to other people with ADHD about what you're going through, and to get ideas (not medical advice!) about how to approach things. If you don't use your name as your login on the site, you can post without people knowing who you are in real life, and so you can have great open discussions. Here are some sites I like a lot:
ADD Forums - www.addforums.com - this site has been around for ages and you can find discussion sections for all kinds of subgroups of people of different ages with ADHD. It is very active. It even has a section for inattentive ADHD!
Women with ADHD - www.womenwithadhd.com - this site is quite new but also very active. I've been impressed with the discussions between adult women who have ADHD.
ADDer World - www.adderworld.com - this is a forum and site set up by a guy who wrote about his own ADHD. It's fairly new, geared towards adults with ADHD, and seems to be pretty active as well.
Here are some caveats: Think before you give anyone any personal information (ie login names and such). Don't mistake other people's experiences for either medical information or scientific information. (Just because one medication/diet/strategy worked for some people online doesn't mean it makes sense for you.)
And a biggy for ADDers -- don't bother with the forums if you will get so sucked in you'll spend all your time there! They are useful, but you can get over-focused there, just like on facebook, or on the internet in general.
Enough lecturing/warning, though, I just wanted to share what I think are some very nice resources. Please share any other places you like in the comments!