Paper books are a good archival medium. Gather the ones you know to be useful and valuable. We will lose the cutting edge of microchips. Draw the line at some more fundamental levels of understanding, directly applicable in the new agrarian stewardship and salvage economy. Math, all basic sciences, sociology, spirituality, philosophy. And make a good gardening system, and get some good hand tools, stainless steel screen, other things that will be very valuable in a minimalist world.