Short but sweet booklets like:
Medicinal plants and roots, Edible plants and fungus, Dangerous and poisonous plants - all based on where you live in the nation so one for various starts.
Basic survival techniques
So much of the store is survival oriented it would make sense and small, focused booklets rather than running around with a 400 page book in a bag are obviously ideal. AMTV can author and copyright the booklets to eliminate a lot of cost either printing them in house or through a local printing service.
In general I think educational booklets that don't go too deep but give you a solid surface for understanding a lot of technologies, fields of science, areas of government, the legal system etc.
To this day the average adult doesn't know the difference between a civil court and the court of common pleas let alone a state court of general jurisdiction, an appellate court, the power of a judge of one of those courts and so on.
Just look at Uniform Commercial Code this should be a course you take in high school if not junior high.
It falls under the jurisdiction of civil law but isn't written by the states it is written by a private interest group and ADOPTED into civil law by all the states except Louisiana.
I've read more UCC than I even care to mention from dealing with various businesses trying to screw me around.