Choose Your Weapon (The Helen of Hollingsworth Trilogy) - Sarah Rodriguez Pratt
Helen lives a double life - high school is spent deflecting the scorn of the "cool" kids, while in another world she trains to slay the dragons who terrorized the fantasy novels she enjoyed as a child. Choose Your Weapon is like Pleasantville meets Mercedes Lackey - where a young woman becomes empowered in fantasy and carries it through her reality. A great read for young adults.