I'm an athiest, but I had go through a lot of reseach, logical reasonings, and lots of readings before I was confirmed of my lack of belief in god(s).
Please read the following books as they'll provide you with more insights to your questions than anyone here in sajha
The God Delusion: Richard Dawkins
The Portable Atheist: Christopher Hitchens
The Believing Brain: Michael Shermer

Hope that helps