A Brief History of Time is Stephen Hawking's attempt to make the vast scientific information concerning the universe and how it's put together accessible to every-day people. While it may be true that you don't need a degree in theoretical physics to get through this book, it still left me with little more than a half-understanding of the information. What's more, as Hawking himself points out, these theories change drastically as new theories and discoveries are made, making parts of this book very out of date. Nevertheless, it's a valuable source that will help you see where many of the most popular cosmological theories of the past hundred years came from. If you've ever wondered about the big bang theory, black holes, and the possibilities of time travel, you should pick up this book.
Updated throughout, a tenth anniversary edition of a now-classic survey of the origin and nature of the universe features a new introduction by the author and a new chapter on the possibility of time travel and "wormholes" in space. Simultaneous.