Start with this one and then read the whole Discworld series. They are humorous books in the fantasy genre, but appeal to people who don't think they like "fantasy". If you don't want to start at the beginning, read "Witches Abroad", "Hogfather", "Soul Music", or..., never mind, just start at the beginning and read them all.
Terry Pratchett: Grannie Weatherwax, Nannie Ogg and Magrat. ~- "We've got a lot of experience of not having any experience" - "But the point is... the point is... the point is we've not been experienced for a lot longer than you." Artwork by Paul Kidby from "Witches abroad" by Terry Pratchett (1948-2015)