I read Stiglitz when I was 16, thats when I decided I'd be an economist one day. The book is dense but not unreadable. Stiglitz makes arguments and then gives specifics, so there are a lot of laws that are mentioned, etc. Its perfectly readable, however, it just might take more effort, he doesn't sit there and bombard you with formulas. "Making Globalization Work" is a lighter read, also by Stiglitz.
Other recommendations: The Return of Depression Economics, Paul Krugman. Probably one the best book to come out after the Economic Crisis of 2007 that really explains the way thought has changed since.
Freakonomics (its not particularly deep, but he applies economics in interesting ways that get people who don't normally read econ lit to check out the field, what he lacks in deeper analysis he covers with creativity).
Friedman is easy to read but he is terribly off on so many of his arguments. Even Hot, Flat, and Crowded is a horrid oversimplification. Thats what makes him so easy to read, he lacks complexity and depth, and is really just on the wrong side of the issue (wrong side in Lexus &, not Hot, Flat). Reading his book will actually worsen your understanding since you'll have to unlearn half of it.
