Check out the website for Arthritis Introspective - it's a grassroots organization that helps you start support groups for people with RA. As well, they maintain a list of support groups that already exist in different areas in the US. You may also want to check out a post I wrote about parenting teens with RA - it has links to resources where you can contact other parents of kids with RA, as well as a link to a message board for young adults living with the disease where your son may find people to connect with.

We also have a number of teens and young adults on this site and I'd recommend that you suggest to your son that he signs up and poke around to see what people are talking about. We are planning an area for young adults living with the disease, but it'll probably take a few months before that's developed. In the meantime, we would welcome hearing from people like his son about what their needs are and what kind of information would be helpful.