I have been reading a lot of post-Apocalyptic books lately. Mostly because I enjoy them. But I believe that there are a lot of valuable lessons in these books such as how long man-made items will last. Which reminds me of a book I read awhile ago - non-fiction, even!
I'm going to suggest you read, World Without Us. The author of this book talks to experts and then explains how fast man-made items will break down. In our bomb shelters, we can store many items but when we eventually emerge, we can expect not to have a lot of things that we take for granted now.
Such as cars - how long is that gas going to be good? How long are the rubber tires going to last?
Such as fresh water - how long will the reservoirs continue to work and push water our way?
Such as food - canned items can last for awhile. But we will really need to start planting and growing things on our own. And how long will seeds last in their packets?
Such as fresh meat. How long can domesticated animals who rely on humans for most things last in the wild? If they do return to the wild, who's going to hunt and butcher them so we have a meat source?
I could go on and on.