It's hard to review this book without giving spoilers . . . I can't talk about any main plot element without giving away something . . . so I'll just tell you some of my favorite things:
1. Bella goes through a period of depression. When she gets to the depths of despair, the months pass without her remembering them. The author tracks the passage of time with the name of each month on a blank page. Very creative.
2. I loved the Romeo and Juliet tie ins--they were a fun addition. Some reviewer somewhere will probably criticize this as being cliche. But it was perfectly fitting to the story and perfect for the genre.
3. The ending leaves you questioning (and hoping) that the two main elements of the first two books in the series will be tied up in book three.
4. Read the author's acknowledgements at the end. It's great to catch such a personal glimpse.
5. This is my own warning: When I read New Moon, I decided to read Twilight again. It was better the second time because I wasn't racing through it to find out what happens at the end. I was able to enjoy all the foreshadowing to New Moon and really appreciate the obsessiveness between Bella and Edward.