So I greatly enjoyed Lewis Dartnell's The Knowledge: How to Rebuild Civilization in the Aftermath of a Cataclysm, but I believe most readers agree that it is more of an outline than a sufficient resource in itself.
But it's still a great book and a valuable place to start when doing this sort of research.
I think it's worth considering what sort of information I find desirable. That will be the subject of this post.
Dartnell's book poses the question: "If you suddenly found yourself without a working example, could you explain how to build an internal combustion engine, or a clock, or a microscope? Or, even more basic, how to successfully cultivate crops and make clothes?"
I suspect that if society collapses, fossil fuels will be a nonstarter; we've plucked all of the low-hanging fruit there. There are options like biodiesel, but, generally I expect to disregard information focused on specifically gasoline or diesel internal combustion engines. I suspect also that whatever fuel and oil remain would be a source of strife and conflict. Internal combustion engines, even perfectly functional ones, would likely be far more plentiful than the juice needed to run them.
A clock? Absolutely important. And a microscope, crops, and clothes.
That's an illustration of the logic I'll use to evaluate information. My goal is not necessarily to reproduce the modern world. I'm not sure such is a good idea. I'm not sure if recreating computers is a good idea. I'm confident that reproducing internal combustion engines is not. Same for nuclear weapons. I might say the same for guns, though I acknowledge they might be necessary for self-defense.
I'm also not sure that I believe we should reestablish a new technological trap, in which we are wholly dependent on, ignorant of, and alienated from the things we use every day. This includes devices that can only affordably be manufactured by exploiting labor, by extracting rare elements from specific parts of the world, etc. That would include most plastics.
I don't really know what precise level of technological knowledge I'm aiming for. Presumably something 19th century at the very latest. Perhaps 15th century, or even earlier, or differing levels in different areas.
I also think there are some things that are often missing from these discussions. Books on the sociology of small groups? About simple politics? About law and order? We need ideas about how to vote in a way that is resistant to gaming, intimidation, fraud, etc. About astronomy, since telling time and location from the celestial bodies will once again be important?
I suppose there's an incalculable amount of valuable knowledge to preserve. I don't even know what I can't think of to list!