The It Girl is the spin-off of Gossip Girl, the main character being Jenny Humphrey. It was created by Cecily von Ziegesar.
You may recall from the last Gossip Girl book that Jenny Humphrey has left Constance Billard in NYC to go to a boarding school- Waverly Academy in Upstate New York. Waverly Academy is filled with rich kids with their secrets. Jenny herself is trying to move into her "New Jenny" role, meaning she isn't going to let people get her down anymore. She wants to be more wild, more in control, more free. So far it seems to be working, as several of the popular guys in school seem to like her already. But can that be because of the rumors that keep following her around?