Civil Defense Manuals online
I remember reading this over and over as a kid, as I expected a nuclear attack at any time.
The illustrations really stuck in my mind.
A lot of the information, especially regarding natural disasters, is still useful and just makes sense.
http://www.gutenberg.org/etext/15158
A 1987 edition of a nuclear war survival skills book:
http://www.oism.org/nwss/
A whole truckload of survival manuals:
http://www.survivalring.org/pdf-index.htm
Lots of historical info and images here:
http://conelrad.com/index.php
http://www.civildefensemuseum.com/
