This book helps teach you programming and understanding systems at a low level. While trying to be entertaining and provides a liveCD to experiment with.
First thing I'd ever seen on the darknet was this bad boy. (Not that it was a terribly efficient way to get an epub.)
Such a bottom-up book. Almost gave up back then, thinking I wouldn't be able to handle assembly, but then what would the point of reading about the hacker mindset be?