This is an interesting discussion - how many of you actually raised your kids up telling them to be atheist and how many simply emphasized science, reason, education, and always questioning things for evidence and the result was the kids on their own decided to become atheist?
I don't have any kids but when I do have kids - I think I will approach it with the aforementioned ways...I don't think one should dictate to a child what to believe but to present reason and rationality and allow them to ask you questions and explore the wonders of the world and the universe.
My daughters know no other way of thinking. We have raised them as open atheists and they are comfortable talking about it with pretty much anyone. We have discussions weekly if not daily about religion and politics, which these days seems to go hand in hand. We have purchased many books about religion and we have allowed them to go to church with their friends. My girls have a hard time understanding why people believe in God at all. My older daughter even went to Mormon church once with a boy she liked. She came home asking why the church would encourage girls to get married right out of high school and not go to college, she was baffled. I think allowing my daughters to experience these things for themselves and ask lots of questions has been great for their own confidence in their atheism. Of course they have both been told they are going to hell, to which they respond that there is no such place. We live in a very Christian community and with that will come people that believe we must worship the devil since we don't believe in God. My advice to anyone raising their children as atheists is to Talk to Your Children! The rest will come. Remember what little sponges they are and also how smart they are. They'll amaze you with their own observations.