From here:
z1235 has been plugging the hell out of Beyond Democracy. Says he’s gotten a lot of positive results by recommending it. $0.99 on Kindle (or even borrow it for free if you have a Prime account.)
Other recommendations for good short ones would be The Law and Anatomy of the State. For more recommendations, I’d check out the One Book for Capitalism thread…but it seems like BD is going to be the ticket. It’s short and (evidently from z’s experience) is quite effective in bringing people around.
You might also check the Courts/Law, Security/Defense (Free Society reading list & threads) from the meta thread.