Nobody mentioned books. The “Foxfire” series contains a lot of information relating to survival. There are many more like them. You’ll need them because no matter how much you stock, it won’t be enough for a really long haul.
There's a Youtuber called "DIY Prepper TV" and he has some good videos, and he mentions various books and I think that was one of them. He's the one who's gotten me on the path to preparing.