It depends on the type of apocalypse. Radioactive might be tolerable if the people aren't clumped together, but if it's a Mad Max like wasteland, I'm not sure if that's the way to live. I'd guess there's already some eccentric people out there who have made their tunnels and are ready to become the great ancestors to Molemen....how many billionaires are out there? 3,000? It'd take 1% for 30 billionaires to think the exact thing and make a giant sized ant farm that would merely wipe out 20% of their fortune for some elaborate Bond-esque underground complex. Shoot, they spend tens to hundreds of millions for an oversized boat just to look cool with their money. As for the plebes and muggles who have to live on the surface....Open source and 3D printing ftw: http://opensourceecology.org/wiki/Global_Village_Construction_Set I forgot about the app that takes a dump of wikipedia, but I think it can run on an Adruino device. Archive the Kahn academy and at least you're above 19th century 'readin, 'ritin n 'rithmitic... So all you'd need is a power source to charge against, a decent smartphone, and some exchangeable parts for maintainability (preferably a sustainable way to manage memory such as flash or HDD, though not required). A hundred 2-year old hacked smart phones for an eccentric is nothing, but more than enough to educate for a long time.
Manuals...textbooks...not that much difference. I'm mostly yanking your chain. When you initially said textbooks, I got an an image of some dude stumbling across the apocalyptic wasteland dragging around copies of his economics, algebra and Texas history books around. Fighting off mutants during the day and boning up on his Keynesian theory by firelight.
If the land is livable after this major event and people can travel without being exposed to harmful radiation/gas/elements, things would be significantly better within 25 years. Technology, power plants, and oil rigs don't just come from nowhere - people build them. With everyone willing to work to build energy infrastructure essentially for free you would be surprised what could be accomplished in a relatively short period of time. I just don't see a tv/movie like apocalypse scenario playing out unless there is no way for intelligent people to congregate or communicate.
hehe. What you just described is 100 times more interesting than what's going on on the the Walking Dead...