Clockwork Angel - The Infernal Devices, Book 1 (Margaret K. McElderry Books, 2010) by Cassandra Clare is a prequel to the author's Mortal Instruments series (which I haven't read yet, but now want to...).
16-year-old Tessa Gray takes a ship to London where she is kidnapped by the Dark Sisters, who train her in transformations. She ends up with the Shadow Hunters who promise to help her find her lost brother. The story has vampires, demons, magic, steampunk, romance (Will or James) and is fascinating and scary.
Book 2 is called Clockwork Prince and is now out. Book 3, Clockwork Princess, is scheduled to come out the end of 2012.
On Cassie's website I discovered she'll be touring Germany, the UK and Ireland this spring.