Trylle Trilogy by Amanda Hocking

Amanda Hocking wrote the Trylle Trilogy--Switched, Torn, and Ascend.

They're self-published. That being said, the writing is very impressive, and she has been picked up by a publisher for her next series. There are a few errors, but you can look past them, and if you can't, well, stop reading. Your loss.
I'm pretty sure you can only buy these on the internet...idk, though. I read them all on my kindle.

The books follow the story of Wendy Everly. She is just an average girl...except she can do this whole thing with her mind that makes people obey her...and then Finn Holmes comes along and changes her life forever. He tells her that she's a troll--but not the 'answer this riddle and you may pass' type of troll, so they call themselves Trylle--and that she is in danger. The Vittra want her for reasons that she doesn't know.
He takes her to a kingdom called Forening where she realizes that everything about her life is a lie. Then she is torn for the rest of the three books between three guys--Finn, Tove, and Loki. It's basically insanity. You must read.

I really liked the books and their stories. It was very interesting, and I will definately be reading more from Hocking. In fact, I'm reading her new one, Hollowland, on my Kindle right now. Enjoy!