Randy Mosher’s Radical Brewing (buy it on Amazon) is not your normal introductory homebrewing book. I’m a little sad that it took me this long to get around to reading it. It should be the second or third homebrewing book you pick up after How to Brew or Complete Joy of Homebrewing.
In my continuing quest to learn everything I can about beer I picked up a copy of Tasting Beer: An Insider’s Guide to the World’s Greatest Drink by Randy Mosher off of Amazon a few weeks ago. They had a sale where the Kindle version was only $3 down from the normal $9, the dead tree version is $11. I would recommend the kindle version because at its core this is a reference book. Being able to open it up on your phone in a bar/bottle shop and search for the style of beer you’re looking at is where this book will shine in the long run.