As an author, I'm frequently asked (twice in 2008 alone) about how a book gets from a writer's mind to the remaindered table at a bookstore.
Luckily for me, Macmillan has created this educational video: "From the Typewriter to the Bookstore: A Publishing Story." By the way, Macmillan will be publishing my unauthorized autobiography, Under the Influence of Powdered Milk, later this decade. Preliminary notes from my editor below.
Anyway, while anyone even tangentially connected to publishing probably knows most of this video's material, it still makes for a nice refresher course.