Yesterday I finished Not Even Wrong by Peter Woit, another book about the problems with string theory. I discussed another book that came out around the same time, Lee Smolin's The Trouble with Physics, here).

They are both worthy attempts at bringing attention to the state of particle physics, but Smolin's is the better book. It's more clearly and concisely written, and better organized. He also does a better job of explaining why string theory was seen as a viable and important idea to work on, which also helps explain why a lot of physicists are un-willing to give up on it.

Woit's book is better at going into some of the mathematical details behind the theories. For the layman, I would recommend reading Smolin's book first. If you are still interested, and want to get more of the details without trying to jump in to the actual papers, then read Not Even Wrong.