Shadow is not necessarily a good man, but he's not nearly as bad as some of the other characters in this book. Shadow is serving time when we meet him for a robbery gone awry. He's deeply in love with his wife, Laura, and is nearing the end of his sentence.
The end comes faster than anticipated when Laura is killed in a car accident. Shadow is released and things just go downhill from there.
In this book, gods walk the earth. Anansi, from the book Anansi boys, is alive and well and very much still the spider god. Each god is kept alive and viable because people believe in them. Once people move on and quit telling the god stories, the gods become nothing.
Shadow is confronted by Wednesday and enticed to work with him. Wednesday is a god, turns out he's THE god. And Wednesday wants to start a war with the new gods, gods of tv, media, computers, you know the things people all worship now.
Along the way to war, Shadow meets up with Laura, who is dead but not really, and several other gods in disguise. Lucy Ricardo tries to entice him with her breasts and gods fall into crumpled heaps. The war is not what it appeared to be and Shadow does what he can to save both sides.
Probably should have read this before Anansi Boys but it didn't matter too much. American Gods is ripe with imagination and vision. A scary vision, but a vision nonetheless.