The Elegant Universe, by Brian Greene
http://en.wikipedia.org/wiki/The_Elegant_Universe
published in 1999 which introduces string theory and provides a comprehensive though non-technical assessment of the theory and some of its shortcomings.
"Into the Universe with Stephen Hawking" a 2010 science documentary television mini-series written by British physicist Stephen Hawking.
http://en.wikipedia.org/wiki/Into_The_Universe_with_Stephen_Hawking
Theoretical Physics For Dummies - http://www.amazon.com/Theoretical-Physics-For-Dummies/lm/RIEQXHWAFMG17
