I stumbled upon The Secret Guide to Computers a long time ago (back when I considered DOS to be a semi-serious operating system). I had never seen any book like it before, nor have I seen it's like since. At the time it was completely chock full of tips, introductory programs for just about every language one could easily get a compiler for, and loads of almost fanatical rambling about computers. I'm pleased that it's still out there, and might even avail myself of the update.
Check it out at SecretFun.com.