There are also different kinds of support groups. We've fallen into one in the last year, through a social skills course that was being offered by the state autism association. difficult child 3 only got to the last session, but through that I met the parents (all waiting outside and talking) and learned about other groups. We have a local disabled kids drama group which I finally got difficult child 3 into a few months ago. He has to mix with kids with a range of disabilities and frankly, I don't think it's working for him, but he's about to move into the older group this year so we'll keep an open mind. Most of the older group are autistic, but there are some brain-damaged and Downs kids too.
The thing is, an offshoot of the drama group (from which the kids were recruited for the social skills group) was the autism support social group in our area. We organise outings on a monthly basis and the kids sometimes meet up at other times. difficult child 3 was going in to correspondence school study days with another of these kids, so they met at school as well as socially. And now, of course, the film they're involved in - a lot of kids from our social outings group are now involved in "Black Balloon" filming, because we're now part of a communication and information network.
Sometimes we get together. Mostly we don't. But when we need to talk, we pick up the phone or email someone. And if you think about it - parents of difficult children often don't get out as much socially. We can't. When we do, we really understand the problems we're each facing, so if a kid is throwing a tantrum we just nod and smile. And offer sympathy once it's settled.
Some support networks work like meetings, with a person up the front talking about new developments or introducing a guest speaker. Some work like a circle of chairs where people take turns to talk. Others work more informally, like a conversational free-for-all. Some include the kids, some don't. Some organise rallies, others take a low profile.
What you need will vary, depending on your needs and where you are in your journey. Not everybody wants to belong to a group. Not everybody should belong to a group. Some groups can become toxic if led by someone on a power trip, or conversely, led by someone too weak to control someone on a power trip.
But one thing is certain - if a group runs well there is power in numbers. There is advocacy, support and strength collectively. Where possible, work with whatever is available. If you want to branch out, try to do so under the umbrella of an existing group, so you don't have to duplicate resources.
Good luck with your search.