The Realm of Althea- Book One: Realm Jumper - The Realm of Althea, #1

When teenagers Rolland and Kimber are magically transported from their inner city neighborhood on Earth to the mystical realm of Althea, they find their childhood friendship strained by different obligations and responsibilities, and budding romances. Gallant Rolland wants nothing more than to protect Kimmi from the perils of this dangerous world; but, when Kimber is chosen to become the rider of newborn dragon Rainess, she must fulfill the duties of the position of dragonrider.
Kimber is determined to become the strong, independent warrior of a woman Rainess needs her to be; and, in the process, she becomes the kind of woman princes pledge their hearts to... Will Rolland be able to protect Kimber from the dangerous enemies lurking in the shadows of this world? Will she be able to save him?