Always a good idea to have certain books covering subjects such as survival, first aid, knots and rigging, how to grow your own food, and how to construct basic shelters and other projects.
If you don't want or cannot afford to buy them, then by all means print the stuff out and keep it handy and protected from the elements. Zip lock bags, etc.
One thing people over look as well is the type of tools to keep on hand. Things like hammers, saws, shovels, axes, screwdrivers are just as important as your water proof matches and MRE's.
I just picked up “How To Survive The End Of The World As We Know It” on Thursday. It is full of tons of useful information.