The Forest of Hands and Teeth by Carrie Ryan is really, really good. If you've never read a zombie novel before I can't think of another that would be a better introduction to the sub-genre. The novel focuses on a young girl, Mary, who lives in a small forest village surrounded by walls that are in turn surrounded by the undead (BTW - I love the fact that my computer's dictionary still doesn't acknowledge the word undead as being legit; somehow the fact that it appears on my screen underlined in red makes me feel like my genre tastes are still edgy and not necessarily accepted as the norm).
Without going into a synopsis, I can only say that Mary comes across as a fully realized three-dimensional character; her wants and dreams are easy to relate to and her wish to see the ocean (something she has only ever head about, as a sort of legend), is heartbreaking in its innocents.
The book has a sequel and I will definitely be checking it out. This is one of those few books that I knew I would need to own within the first hundred pages. Seriously, it's that good.