Off and on since 2000 or so, I've been a member of an online forum that started out as a discussion of Buffy the Vampire Slayer but turned into an all-purpose international community. Now there's a book about my mostly-virtual world: Will the Vampire People Please Leave the Lobby? True Adventures in Cult Fandom (Allyson Beatrice, 2007). It's a series of well-written essays, by turns snarky and touching, on how what starts as a simple online discussion on a specific topic can turn into a real community, warts and all.
I honestly don't know how the book would read for someone who's not a part of that tribe, but I'd recommend you try. Allyson has a flair for dead-on description that make her voice a pleasure in itself. Reading it had an impact on my life: it made me decide to return to one of the online forums she discusses after an absence of nearly two years. I'd left after finding myself at the center of a kerfuffle. It was a great big mess, and I decided the only sane thing to do was walk away from it. I still think I did the right thing, but reading Allyson's book made me miss the place. These are the people I talked with on September 11, when we were scrambling for information and comforting each other and trying to make sense of our suddenly shifted world. These are the people who anxiously awaited updates when I was in labor for four days. They're the ones I shared my triumph with when I finished my first manuscript. And they consoled me through my father's terminal illness and death. So I decided to dip a toe back into the waters there and see if I still belong there in any way. It's still early in the toe-dipping process, but I'm glad I read this book and glad I decided to give it a try. Because internet communities are as real as any other kind. They're not always easy, but a good one is worth fighting for.