Many people don't sulfite, but I do. I use one campden tablet per gallon at every other racking. If the cider will be consumed within a year, I wouldn't bother adding any at bottling. With most of my wines, they are at about 12-13% ABV so I like to age them. I do use sulfites in all of my wines, but at the lowest amount I need to preserve them.
Sulfites are a preservative, as well as an antioxidant. Using them at every racking would be too much. If you don't have an SO2 meter (I don't) using them at every other racking would probably still get you to a 50 ppm concentration.