Hi Mr. Rawles,
I’ve been able to pick up a lot of gear at garage and yard sales. Most importantly, I’ve found many practical books at yard sales and junk stores that sell books for $1 or even just 25 cents each. I was able to pick up a home medical adviser from the 1920s for 25 cents. I have also bought numerous books on small scale farming, canning, food storage, and living off the grid from the 1920s for a dollar each. Much of the information would be relevant to a post-TEOTWAWKI , as it was written for farmers or rural residents that didn’t have access to electricity and largely lived off the land.
I have a few books about working on houses from the post-WWII years since it is before plastics, which has inherent benefits in a survival situation since they will be hard to find at Home Depot. They also have information on how to make repairs that today the answer would be buy a new one, or use a hard to find/expensive par. (Impossible in a survival situation.)
These are the books that I have found most helpful:
The Home Handyman’s Guide edited by Hubbard Cobb copyright 1949
Readers Digest Back to Basics Copyright 1981 (most important by far with general info on everything)
2004 Emergency Response Guidebook (there is a new version every year, its given free to public safety organizations)
The Weather Wise Gardner by Calvin Simmons Copyright 1983 ISBN 0-87857-428-X
The New American Garden Book Copyright 1954 edited by Dorothy Sara
The People’s Common Sense Medical Adviser by RV Pierce copyright 1895 [JWR Adds: Keep in mind that some of the home medical remedies described in books of this vintage (such as “take a spoonful of kerosene…”) are not safe or recommended! OBTW, a similar encyclopedia titled “The Household Cyclopedia“, circa 1881, is now available online for free download . Thanks to reader “TinCan” for sending SurvivalBlog that link.]
Various USDA agricultural yearbooks from pre-1935, these are also great because a fair deal of them is geared towards the farms that existed as family farms and were quite self sufficient.
Also, on another note, for people that live in suburbia it is important to block visibility from neighbors or the street when storing cached gear. For example, I was driving through my neighborhood today and there was a small horse trailer (in neighborhood where livestock is prohibited by the homeowners association) inside a garage. That sort of thing draws attention and others will start rumors “Why does he have a horse trailer inside his garage? What are they trying to hide?” When TSHTF  neighbors will start talking more and maybe something may come up. I hope these books and the advice helps someone. Regards, -Sam