I really want to learn more about coffee, but I think the web is too large and therefore confusing. So I have decided to start with a good book. Which books (preferably below 20 USD) can you recommend? Just a good and informative beginner guide to espresso and coffee in general?
I recommend Hoffman's "The World Atlas of Coffee." He gives you history, tells you about different methods of brewing, roasting, and teaches about growing and processing as well. A very well rounded introduction.
So far as a book focussed more on brewing, I recommend Rao's "The Professional Barista's Handbook." His blog (also linked below) is also a tremendous source.