Hi wtfi54rasm,
You're actually asking for three essential things.
1.) Resources on the validity (or lack there of) of Religion
2.) Resources on the psychology of indoctrination (if not on belief in general)
3.) Resources on atheism (or rather, resources on evidence for a god's nonexistence)
For a great book on the psychology of primitive man, and why religion was possibly introduced into society, the two best books that I am aware of on the subject are Daniel Dennet's, Breaking the Spell - which deals specifically with the indoctrination of man into these beliefs and how to get yourself out of that indoctrination, and Julian Jaynes' The Origin of Consciousness in the Breakdown of the Bicameral Mind which deals with primitive man's mental development, and how they viewed the world through their primitive brains, and thus the development of primitive ideas such as "god".
For resources on the validity of Christianity, the book Misquoting Jesus by Bart Ehrman is a very good introduction into who changed the Bible, and for what purpose. Although he is a bit of a scholarly fossil, and I don't agree with all his conclusions, his work is pretty outstanding as far as it goes. Unfortunately, the vast amount of research one needs to do in order to see all the flaws of Christianity is extensive, and can not be read in a few books. Although, a start would be to read the Bible from cover to cover, and mark down all the contradictions and fallacies within, take notes, and check them when you're finished.
For a specific book dealing with the origin of Christianity, I would suggest getting a copy of my book when it is published.
For an excellent resource on god's nonexistence, I would recommend the message boards on the Atheist Network and the Rational Response Squad websites.
The best to you,
Rook Hawkins
Please help me get my resources so I can continue to historically show the inadequacies of the Bible and early Christians.
My wish list.