I've read all of Rainbow Rowell's books up to this point, and they are all guaranteed to be sweet and funny. They are a guaranteed quick read because once I start the book, I don't want to stop. Fangirl is no different in this regard. 
 Cath is a Simon Snow (think Harry Potter) superfan. Everyone is, but Cath immerses herself in the Simon Snow world by writing fan fiction of the series. It is something that Cath and her twin sister Wren love to do. That is, they loved to do it until they are ready to go to college. The summer before Wren tells Cath that they will not be rooming together. Ever since, things have been tense between the pair. Wren wants her independence and Cath wants everything to remain as close to the same as possible. The thought of not living with Wren doesn't even seem like an option. 
 Cath is kind of set up at the beginning to look like the weaker of the twins. She isn't interested in partying and getting drunk. She really just wants to stay in her dorm and write fanfic. She was so uncomfortable with this change in her life, I honestly didn't know how she would make it. Slowly Cath starts to form friendships with those around her including her roommate Reagan, Reagan's boyfriend Levi, her writing class partner Nick, among various others. We come to learn that Cath has a great voice. She has a sharp wit and good personality. She's not as embarrassing as she believes she is. 
 Throughout the whole story, I really love that despite the pressures the Cath may feel (within herself) to change, she doesn't. She knows what she likes and she may be hurt when people make fun of it (speaking of specifically of Simon Snow and the fanfic) but she knows she loves it and that's good enough for her. And when it comes to those she loves, she'll do anything to make sure that they are ok and taken care of. 
 Rowell's writing is so seamless that Cath's transformation from a shy almost loner to a more confident and social Cath are almost....magical I think would be an appropriate description. I like that the problems in Cath's life don't all necessarily get solved by the end of the story, but by the end you know that no matter what, everything is going to be alright. 
 So far, I love everything written by Rainbow Rowell. Highly recommended!