Eden High Series 2 Book 3 by Jordan Silver

Sian Claiborne is not a happy camper. Just when she was getting into the groove of high school hijinks, her parents decide to pick up stakes. Now the popular cheerleader is off to the ritz and glamor of the Hollywood Hills, where her new school is home to the offspring of Hollywood's elite. Determined to hold her own, she befriends one of the school's outcast on her first day, thus drawing a line in the sand between her and the ever-popular 'Mean Girls'. Little does she care, until she claps eyes on Jace Saunders and almost loses her pom-poms.

Of course the head cheerleader already has her eyes among other things set on Jace and lets Sian know in no uncertain terms that he's off limits. What's a girl to do when the first guy to make her heart go pitter-patter seems to already be taken?