This is an anthology book of post-1900 science writings (essays, anecdotes, poetry) written by working scientists, as opposed to written by non-scientists, and it is supremely excellent. Richard Dawkins has collected them, sorted them, and written introductions to each of them, which put them in context.
Explains atoms and isotopes, planets and satellites, novas and supernovas. It also contains a title essay, which is available online. In it, he explains that there is a continuum from right to wrong, and that it's possible to be righter and wronger. For instance, if you think the Earth is flat you are wronger than if you think the Earth is a sphere. You're still wrong, because the Earth is more like an oblate spheroid, but even that is wrong. And so on.
A pretty comprehensive guide to evolution, and the second book that introduced the gene-centric view of evolution (namely, that genes use bodies — survival machines — to pass themselves on, rather than organisms using genes to pass their traits on). The main goal of the book is to explain altruistic behavior and to dispel the myth that just because genes are selfish, we must (or should) be selfish, and I think it succeeds. The book also introduced the concept of memes (supposed to rhyme with genes), which are units of culture (like a catchy tune or a piece of trivia or a certain way of walking) that are capable of being copied from mind to mind.
This book lays out in a systematic way the evidence for evolution. The first chapter, What Is Evolution?, lays out the basics tenets of the theory. The second, Written in the Rocks, are about (as you might guess) fossils and how they give good evidence of evolution (which wasn't available in Darwin's time). The third chapter goes into vestigial organs and functions, and the various bad designs we find in nature. The rest of the book lays out evidence from the geobiography of life, sexual selection, and so on.
The book is a response to the (on-going) anti-evolution tendency, and directly answers criticisms from that wing, in a detailed and interesting way.
One of the better books on evolution I've read. If you're looking for an explanation of exactly why scientists believe the theory of evolution best explains the adaptations in life (as opposed to intelligent design), then this book is for you.