I read this when i was in my late teens, so that's quite a few years ago now, but i still remember it as one of the best fantasy books i have ever read.
Sabriel focuses on the character of the same name, whose father is the Abhorsen, a necromancer who works to make the dead sleep again if they have ended up among the living.
Near the beginning of the book, Sabriel discovers that her father has disappeared and that it's up to her to leave the safety of her school in the non-magical country and travel into the Old Kingdom to rescue her father.
One of the things i loved about this book was how original it was and how well thought out the different realms and worlds were. Whether i was reading about the Old Kingdom or the river of death and the gates, i found it believable and it does actually read like realism.
With regards to the characters, i have to admit they were the most colourful cast i've read about in a long time. From daring schoolgirl, to talking cats and on to a prince imprisoned as a wooden carving, this is one group of characters i won't be forgetting in a hurry.
The story itself is fast paced, absorbing, funny, emotional and even very romantic at times. I laughed, i cried and i definately read the sequels. Garth Nix is a brilliant author!