I could say a lot, but wouldn't want to spoil it. Get Sabriel (1st book) if you like magic/necromancy/romance grit and gore. don't look them up on wikipedia, the description doesn't give a flavour of the books and spoils it.
These are nothing like Garth Nix's other books, totally different writing style, for a more sophisticated audience.
We bought one for our teenagers, then rushed out and bought the whole series. I was gutted when I finished the 3rd book, and there were no more. Felt like I'd lost a friend.