Actually useful sites
survivalblog.com is way deeper down the rabbit hole than I ever care to go. But if the SHF then there would be no better man to ask for charity.
Preppers are a dedicated and intense bunch of people. Best to start your journey into their world view with a neutral source. Here is what wikipedia has to say about them this week. The article always has good links at the bottom of the article. Note: The internet is not useful after the grid falls.
www.arizonabushman.com has a ton of great videos on youtube about how to make it in the Sonoran Desert, and if the post-apocalypse is anything like riding around in a Mad Max version of america , then this will be useful information.