<< Don't get me wrong on this, but one book you should read, if you haven't already, is the Bible. You don't even have to take it from a religious stand point.
The bible is hands down, one of the most influencial books in western culture. Soo many authors make references to it, that you can miss alot of symbolism or points that these authors are trying to portray. If you are reading any classical western literature, your gonna miss alot if you don't have a basic understanding of biblical stories.
And if you don't care for that too much, so much blood shed has been fought over this book, you might as well read what all the fuss is about. >>
Actually, reading the Bible is what made me an agnostic. My friends and their parents had filled me with a bunch of religion in grade and Jr high school. My agnostic father had me read the Bible, without any suggestion or editorial from him at all. It sure opened my eyes.