Nobody Owens lives in the graveyard, having been brought up there since the death of his family. Taught by inhabitants that range from the dead, to the neither dead nor alive, he learns to Fade and Haunt, and to keep out of the way of the people who are still looking for him to complete what they began with his family.
The blurb on the back, inevitably, describes this as the best book Gaiman has written. Personally, I think that might be pushing things a little, if only because he has written so much else of worth. It certainly compares well against the rest of his books aimed at younger readers, such as Corraline, but adult readers will still want to go for the likes of Anansi Boys, Neverwhere or American Gods first.
That said, this is a highly entertaining book, filled with well sketched characters and bizzare places. I particularly like the ghouls named after their first meal, resulting in names like 'The Bishop of Bath and Wells' or 'The Famous Writer Victor Hugo' and the way Gaiman takes a small graveyard and makes its many corners function as completely differently places, from the burial mound at its heart to the collection of unconsecrated graves over on one side.
Structurally, it's quite an episodic book, which is probably a necessary device when you're compressing someone's entire childhood into a book this size. The result is that the chapters function almost as short stories, which probably keeps them compressed and intriguing, but perhaps limits the extent to which the main plot makes its presence felt throughout. The ending, though certainly powerful enough and beautifully written, ends up feeling quite sudden as a result.
Even so, this is a wonderful book. It speeds along and demands to be read for just a few more pages. It maintains a sense of fun from the first to last pages, and it takes growing up and turns the idea inside out by making it happen in the one place where nothing is going to be normal.