It's pretty tragic how little most people understand about basic economics. Not just with respect to how societies function, but basic concepts like incentives and the law of supply and demand. Oh, and of course No Free Lunch. So in that spirit, here are a couple of economics books that I quite seriously believe everyone should be forced to read. Economics in One Lesson, by Hazlitt Free to Choose: A Personal Statement, by Milton and Rose Friedman Freakonomics, by Levitt and Dubner (this book is just so damn fun to read) and for the hackers: The God of the Machine, by Paterson (Think engineering principles as applied to economics, history and politics. Probably one of the most interesting books I've read in my entire life, even if I don't entirely agree with the thesis.)
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