I just read I'd Tell You I Love You But Then I'd Have to Kill You by Ally Carter. The book is well written, and fun. Cammie Morgan goes to boarding school. It may look like a school for snooty rich girls on the outside, but really it's a school to train female spies! The opening grabs you right in and immediately sets the tone for the rest of the book. I know I'll be checking out the sequel.
Read about author Ally Carter at her website: http://www.allycarter.com/