Trivia: Initially, the bathroom door Jack Nicholson was to axe in was an extremely thin one, made by the prop department to make it easier to destroy. However, Nicholson's technique with the axe was so good (he'd been a volunteer fire marshal) the door shattered into a million pieces, so they had to build a much stronger door to handle his swing.
Trivia: The famous scene where Wendy reads through Jack's accumulated work naturally doesn't have the same impact if the viewer can't read English. Therefore, for every foreign language the film was released in, Kubrick remade this shot with an appropriate cliche in each language - French, German, etc. Also, every page of every manuscript was hand-typed to recreate the realism of typos and misalignments.
Trivia: In the scene where Jack is writing and gets mightily upset when Wendy interrupts him, watch the chair behind Jack. It vanishes and then reappears. This was, however, intentional from Kubrick. The audience was supposed to get a subconscious feeling that something was wrong. Nice touch.