A very readable book about Einstein's physics is Secrets of the Old One by Jeremy Bernstein.
In Secrets of the Old One, Jeremy Bernstein sets out to make Albert Einstein's revolutionary
contributions to modern physics comprehensible to general readers. Relying on nothing more
advanced than high-school mathematics, he not only explains the science but evokes the
scientific scene in which the young Einstein wrote his four revolutionary papers of 1905.
Working very nearly alone and with apparently complete self-confidence, in spite of the
skepticism or indifference of the physics establishment, the twenty-six-year-old Einstein
managed to reveal hidden workings of "The Old One"--the name he sometimes used to refer
to the deity. In the course of this amazingly fruitful year, Bernstein shows us, he had
set out the principles that would eventually turn the world of ninteenth-century physics
on its head, and establish the course of physics for the twentieth century and beyond.
http://www.amazon.com/Secrets-Old-One-Einstein-1905/dp/0387260056#_