As for pop econ books, Mankiw recommends the following:
The Worldly Philosophers, by Robert Heilbroner
Reinventing the Bazaar: A Natural History of Markets, by John McMillan
Thinking Strategically, by Avinash Dixit and Barry Nalebuff
Capitalism and Freedom, by Milton Friedman (economist)
Equality and Efficiency: The Big Tradeoff, by Arthur Okun
Nudge, by Richard Thaler and Cass Sunstein
How the Economy Works, by Roger E.A. Farmer
The Return of Depression Economics, by Paul Krugman (economist, author)
The Road to Serfdom, Friedrich Von Hayek
The Myth of the Rational Voter, by Bryan Caplan
The Big Questions, by Steven Landsburg
Spin-Free Economics, by Nariman Behravesh
Economic Gangsters, by Raymond Fisman and Edward Miguel
The Price of Everything, by Russell Roberts
Peddling Prosperity, by Paul Krugman (economist, author)
The Armchair Economist, by Steven Landsburg
Eat the Rich, by P.J. O'Rourke
A Random Walk Down Wall Street, by Burt Malkiel
Freakonomics, by Steven Levitt and Stephen Dubner
Lives of the Laureates, by William Breit and Barry T. Hirsch