I am atheist. I have nothing against religion, but I don't believe. I love the little church my DD goes to though. It is a really nice comfortable place to hang out. I could see myself getting involved there with everything, but the "god" part. They do a lot of neat outreach stuff. Lots of stuff for kids. It is really small, so I couldn't just slip in and pretend, but I wish there was a "church community" for atheist that provided the type of outreach and social activities that are provided at a church.
Re: So I don't believe in God, but I want to join a church
I second the Unitarian Universalist reply. I'm not Christian, but my plan has always been to raise the boys with an understanding of faith. When they get to be of an age of understanding, then I will let them choose what they want to do. So, with that in mind, I've decided that UU would be the best fit for us. I haven't started going yet b/c the boys are still young just yet.
One thing to keep in mind, from what I've been told, UU varies a lot from church to church. If you find you are not comfortable or like what's going on at one center, then it may be vastly different at another, not neessarily UU that you don't like - if that makes sense.