"The Disreputable History of Frankie Landau-Banks" by E. Lockhart

Frankie didn't plan on becoming a criminal mastermind, it just sort of happened...She used to be part of the geek squad, complete with debate club, and awkward, nerdy friends. But something changes her sophomore year, and she finds herself dating gorgeous senior, Matthew Livingstone. Alabaster Preparatory Academy has a long standing tradition, a secret society called the Loyal Order of the Basset Hounds. It's been around for decades and Frankie's own father was part of this good old boys club. This exclusive fraternity is known for throwing the best parties and masterminding the most elaborate pranks the school has ever seen. The only problem is that it's a brotherhood, which means no girls allowed. Frankie doesn't like to be excluded, and she's used to getting her way. Her feminine competitive nature comes out and Frankie's determined to get into this inner circle, even if it comes with the risk of getting suspended!!