The series starts with Sabriel. In this book, we meet Sabriel and the Abhorsen, learn about Charter Magic, Free Magic creatures, and the power of the necromancy bells. In general, necromancers are evil people that seek to twist the power they wield for nefarious purposes through manipulation of the dead. The Abhorsen is different. He uses his powers to combat the necromancers and keep the dead in Death. When he is captured, it is up to his daughter Sabriel to rescue him and save all of the Old Kingdom and Ancelstierre (non-magic world) from a rising evil.
Lirael starts 14 years after the events of Sabriel. The next two parts of the novel begin 5 and then 10 years after that. The book starts with the Clayr, a group of Seers living in a glacier. Lirael is a child of the Clayr that finds herself as an outcast in her solitary world when she discovers that she does not have the gift of Sight like the rest of the Sisters. Her real adventures begin in the Clayr Library with the Disreputable Dog (my favorite character). We then meet two offspring of the current Abhorsen and her husband, the reigning King of the Old Kingdom: Ellimere and Sameth. After a meeting with a necromancer in Ancelstierre, Prince Sameth is returned to the Old Kingdom by his father where he resumes training as the Abhorsen-in-Waiting. Lirael and Sameth's paths cross while Ellimere tries to keep the Old Kingdom running in her parents' untimely absence.
Abhorsen is the last book of the actual series. In Abhorsen, we learn of the origins of the Charter magic, the namesakes of the Abhorsen's bells, and discover where true allegiances lie with pivotal characters. In an effort to rescue Prince Sameth's friend, Nicholas Sayre, Lirael and Sameth must fight against an army of Undead and quickly expiring time before Chlorr of the Mask is able to release Orannis the Destroyer. With new abilities and tricks up their sleeves, the race is on to save everything they hold dear.
A collection of short stories, Across the Wall: A Tale of the Abhorsen and Other Stories, tells more about the trials of Nicholas Sayre and provides 12 other stories set in the same world. Another short story is available on the official website but I can't find a link right now. A second novella set in the Abhorsen universe, To Hold the Bridge, was due out in 2010, although I have yet to confirm this. A prequel to Sabriel, called Clariel: The Lost Abhorsen is due out in 2013 according to Garth's website. A sequel to Abhorsen has been announced but no release date has been secured and I have seen little about it.
Garth went into great detail planning this series out. The history, interlinked stories, even the descriptions of the bells and their correlation to the Seven Bright Shiners... it is all so complex and rich in detail. The poetry included throughout is magnificent. Even the descriptions of Death and Death's Precincts are magical, fantastic, and totally believable. I am a total fangirl of this series (my cats are named for 2 of the characters after all). I have read it countless times now. I spent a good 2 hours doing a /squeeeee when Garth announced a series of charm bracelet style bells fashioned after the Abhorsen's bells. The cost is really high for me (about $350 for a full set of 7 bells) but they are hand crafted by a silversmith so I could see their worth. Will I buy a set when I finally have the money to do so? Oh yes, you better believe I will.