Most of the snow was made of salt and pulverized Styrofoam.
In the book, there were hedge animals which come to life, but at the time, special effects weren't good enough to create them, so Kubrick came up with the hedge maze.
In the book, the room nuber is 217, but in the movie it is 237. The reason is that the hotel didn't want it to be 217 because they thought nobody would use that room anymore. So they used the non existant romm 237.
"Here's Johnny!" one of the most famous lines in the movie, was improvised by Jack Nicholson.