I agree with everything ommmward said. The book she recommended is excellent.
Just a word of advice. It's true that there are a lot of children with additional needs being home educated but people are people, whether they teach their children themselves or at schools, and there will always be judgy folk who have little tolerance for disability. You will encounter them everywhere you go, even in the HE community. It's not always as welcoming and supportive as we'd like and yes, it depends very much on the area where you live.
But the beauty of HE (among many!) is that you can cherry pick what suits you and your child and if one group doesn't hit the spot, you can try others. Plus, you are always there to support in real time so you can be watchful for situations that might be problematic, and help him to cope.
Also, as ommm has said, don't forget you can still join in with community activities - you're not restricted to HE only stuff, the wider groups are still there for you too.
One thing I always found very difficult in HE groups, as a parent of a child with autism and ADHD, is that in most cases there is no-one 'in charge' and there are no set rules. You can end up with lots of different ways of parenting and no 'right' or 'wrong' in interactions - this can be hard for children who need structure. We had some very unpleasant experiences with children who weren't given parental direction and expected to find their own way in social relationships. It doesn't always work. We did experience some bullying and it was hard to address because there wasn't anyone overseeing the activities that we could report it to. But that's just my experience and not meant as a suggestion that this will happen in your case - just something to be aware of.
Overall, HE is fabulous for children with autism and far better than most schools (especially in the current financial climate, budgets being reduced, less support available). I just don't want you to think that HE will be universally wonderful for your son because it still depends, to a degree, on the other folk you come into contact with.