Neil Gaiman's Coraline is a book which has attracted a mixed reception -- see the Amazon comments, for instance. But Terry Pratchett has described it as a masterpiece, and I think he is right. Philip Pullman admires it too.
Before we get too carried away, however, we might just remember what the word masterpiece really means. In mediaeval days, tradesmen or craftsmen in particular fields often formed guilds, which were trade unions, of a sort, and were the means by which (among other things) the established members of the trade controlled the level of membership of their profession. So, for example, we might have a guild for carpenters or silversmiths. At the end of a long apprenticeship, a young man was expected to produce a 'masterpiece', i.e. a piece of work which proved that he had mastered his craft and was capable of taking his place among the recognised practitioners.
It is in this sense that I agree that Coraline is a masterpiece. It is quite clearly a book written by someone who knows exactly what he is doing, what he wants to achieve, and how to achieve it. Whether an individual reader will enjoy the book is, as usual, a matter of taste.
Coraline is one of those works which are ostensibly aimed at children but which can be read equally well by adults. This particular story is about a small girl, Coraline, who goes through the wrong door (as children do in these stories) and finds herself in a mysterious and threatening world from which it is difficult to escape.
There is nothing particularly original about this tale, any more than the plot of a whodunit is likely to be original. But, as in other genres, the success or failure depends upon how the work is handled. And for my money Gaiman handles his material supremely well. Whether you would actually want your child to read it will depend on the child's age and degree of emotional toughness; the book might generate nightmares in some. And I wasn't entirely convinced by the finality of the ending. In other words, I have a horrid feeling that that nasty thing might come back. But perhaps that's the point; maybe there is to be a Coraline II.
As for links to further info about Gaiman and Coraline -- well, a quick google will bring you a superfluity of possibilities. Suffice it to say that Gaiman is a well established writer with a large coterie of active fans. You might try the Mouse Circus for starters, though it takes a fearful long time to load.