Well what kind of jaw surgery are you having? If it involves moving the jaws then you will almost certainly have it done in a hospital under general anesthesia. Expect to stay one night at the hospital at minimum.
You don't really need to bring anything special but if you have a family member that can be there for you then that would help. Make sure you have a good blender for when you return from the hospital so you can make yourself some nutritious soups.