First published in 2008, Frank Wilczek's The Lightness of Being gets the paperback treatment...
The subtitle of Wilczek's book is "Mass, Ether and the Unification of Forces." What he means by that is: 1) Mass - everyone know what that is; 2) Ether - What scientists once believed was the substance found in the universe through which particles travel (i.e., light); and, 3) The Unification of Forces - A unified theory that would link Einstein's theories on gravity with quantum mechanics (which is essentially the randomness found in the universe at the subatomic level).
Wilczek is a Particle Physicist and Professor at MIT. He won the Nobel Prize in Physics in 2004 for his work as a twenty-one year old graduate student. I won't go into what exactly he won it for, because it would involve multiple definitions of subatomic particles and forces that he was studying. Suffice it to say, his work with David Gross and David Politzer helped revive quantum field theory (quantum mechanics), which had been tagged as fundamentally inconsistent when considering the interaction of strong nuclear forces at short distances. There I go. See how easy it is to get sucked into the phrases that need definition? And I'm a layman, not a particle physicist.
But, this is where Wilczek shows his greatest strength! In The Lightness of Being, Wilczek relates the mind-bending beauty and awe of mass, electro-magnetism, energy, quantum mechanics, etc., with the clarity and playfulness the layman requires.
Definitely check this book out if you have even the slightest scientific curiosity. And even if you are not particularly the scientific type, why not learn a bit about the universe from whence you came?