We're huge fans of this kind of artwork. In fact, we've bought a couple (for not a lot of cash) at auction in the past. If you also have a soft spot for public information posters, you might want to order Keep Britain Tidy: And Other Posters from the Nanny State by Hester Vaizey.
Witty, stylish and now with more than a touch of nostalgia attached, Books! - written by Murray McCain and John Alcorn and originally published in 1962 - has now been reissued. Though technically for kids, it's likely that grown-ups will get the same, if not more, pleasure from it too.