I honestly would say don’t waste your time on the movie, especially if you have read the book. I thoroughly enjoyed the book, albeit slightly predictable, but the movie was so far off kilter I turned it off at the end utterly and completely pissed off. I was excited to learn that Mandy Moore was in it... but then find out she’s a minor character, so that was a disappointment. That’s neither here nor there, however.
So many plot holes in the movie, so many unanswered questions, and the major relationships so carefully developed in the book are very quickly brushed over and barely existent in the movie. There’s no intimate connection and it moves so quickly that to someone who has never read the book, confusion and disappointment will likely ensue.