Okay, wow. Just wow. 
 To be completely honest, I read this because I saw the movie and thought it was entertaining and had some neat concepts. I thought they would be pretty similar, this book and its adaptation, just with more details and scenes they couldn't fit into the movie's run time. I knew (in a narrow, general sense) that the ending was changed, but otherwise I had no concept of how different the book was. 
 Or how GOOD! Because this book was amazing! Easily the best thing I've read since "Mirrored" and "Pillars of The Earth". I really don't get where all the hate/low reviews for this book are coming from. Calling it a "gender swapped Twilight" is wildly inaccurate; Twilight doesn't have this level of character development or world building. 
 It's the story of Ethan, a boy dealing with the recent death of his mother and resulting reclusiveness of his father (so extreme that if there wasn't another responsible adult looking after this kid, aka Amma, it would be a case of child neglect). He meets a girl, Lena, with a lot of the same "absentee parent/strict replacement guardian" issues he deals with, but there's two problems. One, the whole town hates her because she's "not one of them" and two, she has supernatural powers that could literally kill him. 
 The love story is really well developed, it sort of becomes like a supernatural "A Walk To Remember" but without the whole cancer thing. The side characters are well developed too, to the point where I not only cared about the more prominent ones (like Link and Ridley, or Macon), but also Ryan and Reese and Del. Larkin, who was barely a footnote in the film and therein actually seemed like he wanted to help Lena, plays a bigger and Darker (pun intended) role in the novel, and it made for an awesome build up to the end climax. 
 Another neat thing is the meaning of the title in context of the book. I was under the impression that the titular "Beautiful Creatures" was a reference to the witches/casters. Toward the end it's revealed it is not. HUMANS/Mortals are the so called Beautiful Creatures. Which I thought was surprisingly bittersweet. 
 So do I reccomend this? Yes, after all, I LOVED it; BUT maybe not to everyone. There are a couple elements of the supernatural portions of this novel that could offend readers (dead people stopping time, psychic attacks, possession... That kind of thing). So read with caution.