Give them some Pratchett, Lloyd Alexander, Brian Jaques et al, but don't forget:
-- C. S. Lewis to butter them up for a bit of future religious indoctrination.
-- George Orwell (1984 in particular) to show them how the world really works.
and some..
-- Philip K. Dick to fuck them up, send them slowly insane and introduce them to the wacky world of curious drugs with all sorts of exotic side-effects...