I liked The Selfish Gene a lot, it definitely stuck with me. But parts of it do get a little tedious. Darwin's Dangerous Idea by Dennett was also good. There are others, like The Blind Watchmaker, but I haven't read it.
More recently I read Why Darwin Matters
by Michael Shermer. IMO, a GREAT
first book to read on the subject.
(I also found Monkey Girl
to be very entertaining, while covering some of the science. And it shows you where the U.S. is legally on the subject, as well.)
In any case, you can get by with out knowing a lot about biology.
I realize you specifically asked for books but I have to add these two resources:
- First, check out this thread that started a here a few months ago: free DVDs
So far I've watched the one with Ken Miller lecturing...very good.
- Finally, check out some great web resources, like http://www.talkorigins.org/