Beth-Lock:
What exactly are you trying to get out of the group?
If you're reluctant to join a group, maybe you should start off by finding a group that isn't all secretive and goes to public places (usually clubs that aren't all that public). Then ask just fire off an email saying that you're a CD and you'd like to just go out and say hi. Then you can get to know people who aren't terrified of going in public.
I know there are a few "support groups" around where I live -- the type that want to give you an interview before they tell you where they meet. One of them is run by a girl who shows up every now and then at a club I like to go to en femme, and she's always ... umm ... well, she behaves very inappropriately. I'll leave it at that.
There are good groups and creepy groups. The more secretive ones certainly seem more creepy to me.
Just make sure that whatever group you're looking into approaches crossdressing in a way you agree with. For example, Tri-Ess is very specifically a group of heterosexual non-transgendered crossdressers. They do not allow homosexuals. They look down on queens and transvestites. They have a very narrow margin of what they find acceptable crossdressing. If you get much of a thrill out of it, you're a pervert. But Tri-Ess wants you to actually identify with your femininity. But if you identify too much with your femininity and get a twinge of bisexuality, or feel you're transgendered, then they don't want you, either.