Book: A Brief History of Time: From the Big Bang to Black Holes
Author: Stephen Hawking
Published: 1998 (Bantam)
I will read about theoretical physics until I understand it, dammit, and Stephen Hawking has helped me get more of the way there.
He explains everything from subatomic particles (quarks make up protons and neutrons and electrons, rightright, but my brain can't picture "packets of energy" - I keep thinking of Taco Bell sauce) to the Big Bang in clear language with a vague hint of humor once in awhile that maybe works better out loud but is appreciated nonetheless.
My favorite parts were about black holes and anti-matter (which apparently runs on imaginary numbers and calculus).
Hawking also outlines what he means by theories and emphasizes the testability aspect and talks about different ones in history and why they came about and how/why they've been discouraged or become popular.
It's a great tour of astrophysics and even more remarkable when you think about how he had to write it. Bookshelf!