Phil Plait's Death from the Skies! is a great book about astronomy. What makes it particularly special is that it's not about astronomy per se, but rather about astronomical phenomena that could kill us. From asteroid strikes to the heat death of the universe, it talks about them in colorful detail.
I had known about all of the things that were discussed in general terms, but the book goes into details I had no idea about, such as the specific way a nearby supernova could kill us or neutron stars possibly turning into white dwarfs in the far, far future. For someone without much knowledge in astronomy, it's a great way to learn about the subject. In fact, the threatening nature of what is being discussed is more like a thin pretense to talk about interesting astronomy, which in no way diminishes the enjoyment factor.
Fortunately, Phil Plait reminds us that it's very unlikely that most of the things in the book will kill us, and for those that are almost certainly going to kill us if we stay as we are, they are either billions of years or an ungodly amount of time off (unless dark matter life forms are deliberately extinguishing stars as in Stephen Baxter's Xeelee Sequence), so no one should feel the need to sell off all their worldly possessions and prepare for the end of the world in despair. Although it should still give us a sense of perspective as the chance of myself dying from an asteroid strike is larger than the chance of myself dying from terrorism.