The title is a bit over dramatic but, per the title, if you could contribute with one piece of knowledge to a book that every single individual should learn from in order to kickstart a civilization, what would be yours?
My personal choice would be the process of soap making, from scratch.
Resist the urge to fall in line behind a “strong man.” Once a community is beholden to an individual, it’s tainted.
The book should definitely recommend a system of government.
I would say directly elected council members with brief term limits, to avoid concentration of power.