Afterworlds is a book told in two storylines -- the first, that of Darcy Patel, the author of the book Afterworlds, who writes the book in a month during high school and is very quickly picked up by a publisher. She puts college on hold, and moves to New York to write the rest of the series and get some serious exposure to the writing world; the other, that of her protagonist, Lizzie, who finds she can move between the world of the living and the world of the dead following a terrorist attack, and who just wants to make things work, protect her friends, and maybe have a little more to do with this mysterious boy she's met in the other world.
Unfortunately, I had to put this book down at around 40%, because both Darcy and Lizzie were just too shallow for me to deal with well, and that's fair, because I'm not the target audience. I was gritting my teeth during Darcy's portions of the book because it was just too... you know, handwavey. She's hanging out with tons of authors, and it's all so easy... I ended up looking forward to Lizzie's parts of the book, but even then, there were times I just wanted to yell, "Dude, really? Don't be a dumbass." After too many of those, I realized I just wasn't enjoying myself and moved on. Again, I am not the target audience -- a mid-teen range would be very much at home in this book.
Related: I am very, very glad to see young adult starting to look at nontraditional relationships and sexual orientations. Kudos, Mr. Westerfeld.