Best prepping reference book?

It really depends, but the most basic advice is to probably avoid anything targeted specifically at the survival / prepper crowd. They are usually rife with bad advice and things the authors read on the Internet and then repeat, inaccurately. The reality is that there is no author with meaningful knowledge and experience in every facet of prepping.

For everyday preparedness (which should be your focus), there are good non-prepper books on fiscal fitness, financial independence, investing and asset diversification, home maintenance and repair, emergency medicine, etc. There are defensive driving courses you can take, first response classes, there are self-defense / CCW trainings.

For larger-scale disasters, there are city and county response plans that are probably worth sifting through. The NWSS book is probably the only "prepper" recommendation I'd make here, and that's because it's been written a long time ago.

If you're seriously worried about some sci-fi civilization-ending stuff, there's plenty of reference books that may be useful, but again, they shouldn't be of the "prepper" kind. Get some books on gardening and farming, get some medical manuals (perhaps Forgey's "Wilderness Medicine", which is aimed at hikers), "Desk Ref", maybe "Henley's Twentieth Century Formulas Processes and Trade Secrets", stuff like that.

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