Used books. Buy from Amazon. They're dirt cheap. Ideas - without knowing what the event entails: 1. First aid 2. Home medicine 3. Edible local plants 4. Hun

Used books. Buy from Amazon. They're dirt cheap. Ideas - without knowing what the event entails: 1. First aid 2. Home medicine 3. Edible local plants 4. Hunting, especially building traps from local materials and deploying them 5. Low-tech water purification techniques 6. Basic carpentry 7. Newton's Principia, because at some point things will start getting better. Electronic media require too much infrastructure to use. They degrade much faster than paper. Books on electronic media can be collected - just don't expect to be able to use them. If the event is known, then the book list can be adjusted. For example, if it's nuclear, then "The Nuclear War Survival Guide" is a must-have: https://en.wikipedia.org/wiki/Nuclear_War_Survival_Skills https://en.wikipedia.org/wiki/Nuclear_War_Survival_Skills