The name of the book is "Elantris," and it's by a new author, Brandon Sanderson. It's easily the best fantasy book I've picked up in a while, it's a single-book as opposed to a series we'll have to wait forever on, and it's just ultra-super good.
He has a website, too. I think there's sample chapters up there, and he's adding annotations and "deleted scenes" to his website for when you finish the book.
I can't recommend it enough. It's excellent.