Three and a half. World Beer Guide is an approachable introduction to the vast world of beer, its history, styles, and regional nuances, from a renowned and award-winning beer writer. It's dated now, and extremely Euro-American-centric (including a bit of classic tongue-in-cheek British humor and a particular bend toward British pints), but quite insightful. Many breweries and mentioned pubs will have closed by now, since it's creeping up on its 15-year anniversary, and other regions of the world, and even regions within the United States, have developed vastly in the last 10-15 years in terms of beer. Still, this feels like a beer shelf staple--and even better if there's an anniversary edition coming.