Been spending quite a bit of time, here and there, over at ADD Forums.
[Why ADD? I have no idea, seeing as it is a general ADHD forum.]
So many people to connect with. Constant feeling, whilst reading, of "oh wow, me too!"
Seems like a very strict ruleset on posting, especially when the majority of the users are going to have ADHD... But there seem to be lots of friendly people there, either way.
A great source of information, from people living with it directly, or indirectly, through family, partners, whatnot, too.