Maria Shaw's Sun Sign Book
Maria Shaw's latest book is a complete giude to all the signs in the zodiac. She gives you the basic personality type of each sign as well as what kind of friend they are, how they are at work and in love.
The book has a extensive section on compattibility (i.e. which signs work best with which). Shaw also tells you which are the best places to live and visit for each sign. I was surprised to find Rochester, MN was a good place for me, a leo, to live since I had just stopped there randomly while on a road trip and said I'd love to move there!
She also puts in each sign's yearly high cycles and low cycles, so you know which times are best for success and which time periods you'll need to work harder.
This astrology book has everything you need to know about each of the signs and I would highly recommend it!