For a truly incisive reading into Genesis, I highly recommend Karen Armstrong's In The Beginning. She goes into some of the really ambiguous themes involving the relationship humans have with God, good and evil, moral grayness etc. Ironically, because she's so critical and blase about the textual errors and contradictions it's almost unreadable for a Christian.
http://www.amazon.com/In-Beginning-New-Interpretation-Genesis/dp/0345406044