Of Fey and Gabble Ratchets by Alison McCaull

Sandy McTavish is a seventeen-year-old girl with the usual high school problems--snarky girls, lack of a love life, and a statistics class that makes her brain hurt. To top it off, damned spirits are after her soul. Sandy has been taught by the best, though. Her mentor, a faerie named Drambuie, was sent to show her the ropes in battling the spirits and the black demon dogs that they ride. It is now Sandys job to protect those in danger of having their souls ripped away by the damned. Only a select few know her secret, including her best friend Anita. Sandys life becomes both more interesting and more confusing when a new boy named Nate arrives at her school. Her clandestine life has left little time for romance, much to her dismay, but she finds herself drawn to Nate. With threats to her family and friends growing ever stronger, Sandy struggles to find a way to protect them. Will she mandage to get close to Nate and still keep those she loves safe?