I've been a fan of theoretical physics for a long time, but had never actually read Dr. Hawking's wildly popular A Brief History of Time. I got a coupon to buy it for $2 and went for it. Even if you're only interested in science or the history of science, regardless of your own science ability, I'd recommend this book. It's highly approachable.
The first 80% of the book describes how we came to know what we do know about the universe. It's amazing how cleverly people can discern truth from a pittance of data available from the stars.
The book paints an informative picture of human nature. It takes us a long time to embrace the truth when it happens to conflict with our notions of tradition, right, or beauty. For example, regarding a universe that expands, Hawking writes, "This behavior of the universe could have been predicted from Newton's theory of gravity at any time in the nineteenth, the eighteenth, or even the late seventeenth century. Yet so strong was the belief in a static universe that it persisted into the early twentieth century." Humans love to grow attached to ideas, regardless of their truth or utility. It's cliche that good ideas are initially opposed and discarded, and it's apparently true in the history of cosmology and theoretical physics.
The final 20% of the book describes speculative theories that haven't yet been tested. This part of the book is not as fun to read. It lacks the anecdotes of creative discovery that make the first part of the book so fun: finding that a theory agrees with natural observation, or making observations that hobble all known theories. If you want to focus only on the best parts of the book, you can skip chapters 10-12, and perhaps chapter 9. For that content, your time may be better spent skimming Wikipedia articles about the arrow of time, wormholes, and string theory.
