I'm tempted to say "a university library" as the short answer. More specifically, whatever I could get from the science and engineering departments. Pick the classic works in each field if you have someone to filter them. Look for stuff that's more universal than specific to the way we've done things - in computing terms, you want The Art of Computer Programming and not The C Programming Language.

In the short term, anything you can find on farming and primitive medicine - all the stuff the better class of survivalist would have on their bookshelf.