A bunch of texts about computing:
My friend David Smith has ferried to me a first edition of Ted Nelson's Computer Lib/Dream Machines (1974). This is extremely good. Computer Lib established the computer as something with which people could be creative; something with which people could create art (oh, and make their lives better).
I also have Doug Engelbart's Mother of All Demos (1968) on DVD. He had it at a conference I was at, and was copying it for a friend... I was nearby and happened to have a DVD burner... I asked if I could snag a copy. It's pretty good quality; I'm very pleased.
Both Engelbart and Nelson read Vannevar Bush's 1945 essay in the Atlantic Monthly, As We May Think. Now that'd be an issue to own. Bush put the US scientists on a war footing, and in this article gave something back in the form of the memex: a kind of hypertext, knowledge-management device for linking and sharing articles and pictures, based on microfiche and cameras. Engelbart read this article as a radar technician in the Philippines, put the ideas together with the radar screen he used, and realised that computers didn't need to be used just as calculators to figure out ballistics--they could be used as personal helpers, in collaboration with people in an interactive way. The 1968 demo included co-working, hypertext, links, outlines, cursors, video conferencing, and the mouse.
Another book I have is Lion's Commentary on Unix 6th Edition (1996 reprint). It circulated illegally for some time, only being published 20 years after it was written. The whole operating system is short - less than 9,000 lines - and it rewards reading. Want to know what a process is? Here you go. And a file? It's in there. Magical.
And so three questions: