Clockwork Angel, Clockwork Prince, and Clockwork Princess by Cassandra Clare. (479, 502, 570 pages. 1551 total)
Having read and enjoyed Clare's Mortal Instrument series and with this having a stronger steampunk influence, I was quite looking forward to reading this trilogy.
Infernal Devices follows the life of Tessa Gray who is kidnapped as she arrives in London and thrust into the world of the Shadowhunters. Not sure whom to trust and unsure of everyone's motives for "helping" her, she quickly has to pick sides in a looming war or watch everything she loves be destroyed.
While the Infernal Devices trilogy can stand on its own, I would highly recommend reading the Mortal Instruments first. A lot of information about the world of Shadowhunting is assumed to be common knowledge, and therefore explained in less detail. I feel this could detract from readers enjoyment of the series.
Note: In writing this post, and trying to link the catalog back to this page, I discovered that this series has been adapted into a Manga! Stay tuned for a review of that adaptation.