Paranormalcy by Kiersten White.
synopsis (from Ms. White's webpage):

Evie’s always thought of herself as a normal teenager, even though she works for the International Paranormal Containment Agency, her ex-boyfriend is a faerie, she’s falling for a shape-shifter, and she’s the only person who can see through paranormals’ glamours.
But Evie’s about to realize that she may very well be at the center of a dark faerie prophecy promising destruction to all paranormal creatures.
So much for normal.
i am SO glad to say that this was not the case with Paranormalcy! my rating: 4.6
this book rocks. the voice, the paranormal creatures, and the story were all wonderfully fresh. reading Paranormalcy was like a splash of cool water--tingly, exciting, and at times, downright startling. even when i thought i knew what was going to happen, i really didn't. the story was utterly unpredictable.
my one complaint: too much was left unfinished! but i guess that's where the sequel comes in...eventually. bleep! i hate waiting for a good book. please hurry, Ms. White!