"Home Brewing - the CAMRA guide" by Graham Wheeler is a good starter level book. It is very biased towards British Ales, but that's to be expected when it's put out by CAMRA. Rather putting down of European lager beers, but a good read for ale brewers.
Also by the same author & publisher with input from Roger Protz is "Brew your own real ale at home". Plenty of all grain recipes & some malt extract replacement recipes for only British ales.
Over in the States, Charlie Papazian has many books published about homebrewing. Two that I have gotten hold of in brewstores are "The new complete joy of homebrewing" & "The homebrewers companion". Both these books are very good at explaining brewing techniques for homebrewers. And they aren't so biased to a few styles of beer like CAMRA's offerings. I'm sure any other brewing books by Mr. Papazian would be a good read too, there's not much this man doesn't know about beer & brewing.
I've used these books for years as references.
Personnally, i've found George Fix's book to be just a wee bit too technical for homebrewing applications, but it sure does give a very good insight into what commercial brewers have to know to ply their trade.
Uni bookshops are a very good place to get books at a reasonable price, especially if you are a student.
Cheers, :beer: