As a philosopher, if I were speaking to a purely philosophic audience I should say that I ought to describe myself as an Agnostic, because I do not think that there is a conclusive argument by which one prove that there is not a God. On the other hand, if I am to convey the right impression to the ordinary man in the street I think that I ought to say that I am an Atheist, because, when I say that I cannot prove that there is not a God, I ought to add equally that I cannot prove that there are not the Homeric gods.
—Bertrand Russell, Collected Papers, vol. 11, p. 91
Personally I am religiously agnostic, a belief formed by my own accord when I was in my early teens, or perhaps a bit before that. Richard Dawkins, Daniel Dennett, Sam Harris, and others have all written interesting tomes on religion and atheism/agnosticism. Another nonbeliever who has jumped on the atheist bandwagon (i.e. well-known, controversial, book-writing) is Christopher Hitchens, though his latest book, "God is Not Great", is disappointing in its logic of blaming (organized) religion for all of the world's problems. Dawkins, a famous evolutionary biologist — finding his way into the spotlight with his breakthrough book "The Selfish Gene" — presents an empirical, scientific argument against the belief in god in "The God Delusion". Dennett is a philosopher; Harris is well known for his book "The End of Faith".
The secular skeptics of the organized religion that has shaped human civilization for centuries are out in full force; as are the more closed-minded religions fundamentalists and apologists using logic even the worst atheist wouldn't dare utilize. To some, however, atheism might be just as much about blind faith in or against the premise of a higher being (i.e. God) as Christianity, etc.
As a rule of thumb, it's good to keep an open and rational mind — but not too open. Stick to your ideological guns, but fill them with logical ammo too to bolster your side of the debate.