Designing Great Beers: The Ultimate Guide to Brewing Classic Beer Styles

An excellent reference for brewing beers to style, this is the sort of book you find yourself going back to frequently. Each chapter provides a short history and description of a beer style, followed by an analysis of the ingredients/techniques for brewing that style. The major weakness is its utter lack of Belgian beer styles, mostly made up for in Brewer's Publications Belgian Trilogy. I love how it provides ranges, allowing you to experiment with some certainty you're in the right ball park.

Hey, I'm a home-brewer. What's not to like? Is a little advanced though.