Yeah, it depends on where you're at and what you've got already. How to Brew is the gold standard it seems for a first book. There's a free version if you want to check it out online (http://www.howtobrew.com/
), but there have been several new editions in the print form with quite a few updates, so I'd suggest spending the money and actually buying the book. The Complete Joy of Homebrewing is another good beginner's book that I actually started with instead.
After that, there are a bunch of books that will depend on where you want to go. Here's the order that I wound up going in if that helps at all:
Brewing Classic Styles is a good collection of recipes and descriptions of different styles, so a good place to start as you're trying to move on from kits to putting together your own recipes.
Designing Great Beers is excellent for recipe construction once you've decided to stop just adjusting recipes and want to start making your own recipes.
New Brewing Lager Beer would have been another good beginner's book, but I got it specifically because Noonan does a great job of describing decoction mashes. Its not just about lager like the title implies, its generally a good all around book but was kind of redundant after the previous beginner's books with the exception of the decoction section.
Radical Brewing, Wild Brews, Brew Like a Monk, Yeast, Farmhouse Ales, and Brewing with Wheat are all getting into more specific areas of brewing. Any would be good once you've got the basics down if you want to start getting more advanced in a certain area.