Ditto what the previous two posters said. I went through stages -- investigated other religions, and decided I couldn't swallow them, and moved toward agnosticism based on several serious questions I have about what kind of God would create a world where so much hurt could come to so many innocent people, and yet people who claim to represent him often get great wealth at others' expense.
Atheism simply means one personally doesn't believe there's enough evidence for a deity such as has been described or invented by mankind. It doesn't have to be dogmatic or say that there can be no god, but atheism just states that on balance there isn't enough convincing evidence for such a being.
The JW's turned me off to religion. Investigation and contemplation made me agnostic and then atheist.