Welcome to DC816.org. We are a DEF CON Group based in Kansas City. Please add yourself to our mailing list or follow @DC816 on Twitter. We hope to see you at one of the events on the calendar!
How do I join? Just express your interest through any medium (e.g. e-mail, Twitter, the forums) and you're in. There's no real joining to be done- we are an open group, accepting of all.