whats the best general reference book for offgrid skills?

We have a copy of (I think ) back to basics, by Abigail Ghering. Its been pretty good.

Theres been a lot of advertising about "rebuilding civilization" as a book lately.

I'd like a book that goes into addition detail on complex projects and skills that might be beyond the ordinary: like basic diy welding, saltpeter production, leather tanning, biodiesel and ethanol, electrical circuit reading and repair, and small scale machining.

Is there a go-to reference you choose for complex topics or do you find a separate book or 5 for each topic is necessary?

I bought a copy of Moving Heavy Things for my reference library already. Been looking at "
   An Elementary Treatise on the Mechanics of Machinery: With Special Reference to the Mechanics of the Steam-Engine " just because its valuable knowledge but I lack the machining knowledge even if I understood steam engine principles!

In person book recommendations are more necessary than ever in today's world of AI books.

I have been meaning to read the Foxfire books for some time now, but haven’t gotten ahold of them. I should check the library system. But those are considered quite classic. They record traditional skills from the Southern Appalachian mountains.

Looks like Internet Archive has vol. 1: https://archive.org/details/FoxfireVol1/page/n143/mode/1up

Reading a lot of ethnographic material helps, especially auto-ethnographies (people writing about their own traditions). (Foxfire is an ethnography as well.) For instance Buffalo Bird Woman, or Lucy Thompson’s To the American Indian. Look also at the Native American Ethnobotany Database. http://naeb.brit.org/ (A lot of my research has been related to Native American sources.)

Townsends youtube channel—not a book but has a lot of useful information about numerous old fashioned skills. Many many cooking videos but also others. https://www.youtube.com/@townsends