What sort of detailed knowledge can we accumulate that will allow a reasonably competent person to reconstruct basic technology with common materials that would be lying around a post apocolyptic world?

There have been a number of questions posted to Fluther over the years asking how you would survive a societal or technological collapse, or a dramatic reduction in human population.

I want to know what sort of steps one can take to rebuild civilization after such an event?

How can we “reboot” technological civilization quickly from an agrarian society?

For example, electricity. Most people who are scientifically minded know that to generate electricity, you spin a magnet inside a coil of wire. Connect that spinning magnet to a fan blade inside a pipe at the base of a waterfall, and you can have a primitive hydroelectric plant. But does anyone know how to construct such a thing from basic parts?

For another example, refrigeration. Again, most people know that to build a refrigeration system, you compress a gas (doesn’t have to be Freon, any compressible gas will do, such as ammonia), send the compressed gas through a series of back-and-forth pipes welded to a bunch of thin sheets of metal (otherwise known as a radiator), then send the compressed gas though a thingy that will relieve the pressure and send it through another radiator, and ‘round and ‘round. Put a fan against each radiator. And put the radiator of the high-pressure side outdoors, and put the radiator of the low pressure side indoors, and you have air conditioning (assuming you have electricity to power the motor to drive the compressor). But exactly HOW do you compress gas, and HOW do you expand the gas so that it just doesn’t equalize pressure everywhere and not do anything?

Most people also know that if you take a lead plate, a lead oxide plate, put them in a glass vat and add hydrochloric acid, you have a powerful battery. But is that all there is to it? Or is there some detail missing that would cause our battery not to work if built like that?

How about paper?

Glass?

Steel?

I guess what I’m getting at is: what sort of detailed knowledge can we accumulate that will allow a reasonably competent person to reconstruct basic technology with common materials that would be lying around a post apocalyptic world?