The book is the basis for the movie Blade Runner by Ridley Scott and featuring Harrison Ford. I watched the movie many years ago, but it was on network TV, so it was edited. Plus, it's a long movie to begin with, so with the commercials, it was, let's see... Well, let's just say I fell asleep and never saw the end.
Philip K. Dick also wrote the novel A Scanner Darkly and short story Minority Report, and since I enjoyed both of those movies, I figured I'd give the books a try.
I wasn't disappointed in the least. The book is full of twists and turns, and is almost impossible to predict what's going to happen next. Rick Deckard is a bounty hunter employed by the San Francisco Police Department to track down and 'retire' renegade androids. I don't want to give too much away, but he sees a lot of action in the single day the book takes place during. If you enjoy Science Fiction, and like stories that delve into the psyche of man, then this is for you. In many regards, the action plays second string to the mental journey Deckard undergoes as he ends up reevaluating his morals and beliefs. His interaction with the androids he kills is the vehicle that causes this change, and nearly costs him his life in a few instances.
I can't really compare it to the movie, since I remember so little, but some things in the book immediately strike me as unfamiliar, meaning they're not in the movie at all. The changes I remember simplify the story on the big screen version, but the overall idea remains the same, which is more than can be said of many other adaptations.
The book is meant for adults, so I don't recommend it for younger children, but if anything I've said interests you, go and give it a read, you won't regret it.