Years ago when I was a kid I read Lucifer's Hammer by Niven and Pournelle. It's about a comet apocalypse and the aftermath. Ensemble cast. One of the characters is a scientist who is diabetic, and while he knows how to get insulin it takes slaughtering a cow a month, which means he needs to have big allies and make himself worthwhile. One of the things he does is take a huge amount of reference books, quadruple bag them, and hide them in his septic tank. As part of the treasure he offers to be taken in.
This seemed like a great idea, so I bugged my mom and starting at Christmas I got an encyclopedia set called "The Way Things Work", which was an illustrated encyclopedia of technology. I see a 2 volume set from 1971 on Amazon, but this was around 20 thinner volumes.
Anyway, that's what I'd grab.