The Martian Chronicles is a series of loosely connected stories about man's attempts to colonize Mars in the shadow of a pending nuclear war. It's not the easiest book in the world to review, like most collections of short stories, but it manages to feel cohesive despite its episodic nature. The stories are tied together by vignettes that are often a page or less. While researching this book, I found that the interstitials were influenced by the similar ones in The Grapes of Wrath, which I thought was interesting.
Most of the stories in the collection were written for outside publications initially, but they are tied together by their chronology, some of their characters, and the themes of the book. Several of them are thinly veiled attacks on colonialism, as the humans come to Mars and completely (and intentionally) destroy Martian civilization. The other theme is man's insignificance in the universe, and most of the stories touch on both of these, pointing out the foolishness of decimating other cultures when the conquering one will eventually die out itself.
The characters in these stories are diverse. There are a couple groups of astronauts, a man who wants to start the first hot dog stand on the moon, a Martian woman trapped in an unhappy marriage, and, in perhaps the books most famous section, There Shall Come Soft Rains, an automated house that keeps running, completely unaware that it's occupants have been dead for a year. There's an interesting connection to Bradbury's other famous work, Fahrenheit 451, because the house in the story is very similar to the one occupied by the main character of F451.
Most of these stories have a pitch black sense of humor to them, particularly the second expedition to Mars. The astronauts arrive and can't figure out why no one seems surprised or excited to see them. They're finally taken to a large hall where the inhabitants are thrilled that they're there, but the group quickly realizes the inhabitants are insane, and the astronauts themselves are interrogated, declared incurably crazy, and euthanized. Somehow, this story is played for laughs until the denouement which is, really, kind of disturbing.
I guess at this point I'd characterize myself as a fan of Bradbury, and anyone who liked F451 or his other short stories collections would be well-advised to read this as well.