When I first started hacking, Steven Levy's book Hackers had just been published. It was an important piece to the puzzle, despite being about the history of hacking and not a technical DIY book. The DIY stuff was easy and common. Local bookstores all had programming books for your system of choice, and magazines full of source code. Hackers in many ways showed me the big picture. It also pointed me in the direction of Ted Nelson's Computer Lib – Dream Machines.
Computer Lib was privately published 9 years before I started hacking, and despite my best efforts at the time was unable to find a copy until I chanced upon the now closed Whole Earth Store in Berkley, CA while on vacation in 1989. They had, in the book section just past the sales display of every Swiss Army Knife in production (at the time), the 1987 Microsoft Press reprint.
Thirty-two years later, I find myself dusting these works off and giving them another read. After having worked professionally with electronics and computers since I was 17 (my first job was fixing consumer electronics at a TV shop up the road from my high school), I've decided it's time to move on and do something else for the second half of my life. Computers, electronics, and of course hacking as always will remain a hobby, and a little tech knowledge will come in handy where I'm going, but when I get my (not a CS or EE) degree I won't be wrenching on computing iron or cranking out code on Maggie's Farm no more.