A room thermometer for the whelping box. F. Some kind of identification. I like to put a different colored ribbon on each puppy as it comes out. This helps keep track of how each one is progressing as time goes on. You will have to change ribbons as the puppies grow, so a good idea would be to get rolls of different colored ribbon on sale somewhere.
Some people use different colors of nail polish and dab a spot on the puppies' heads.
Small, sharp scissors for cutting umbilical cords. Mom may bite it closer, or it may break off closer, but don't you do it. Puppies get pneumonia from having birth fluids in their lungs, and they die easily. Clean hand towels, enough for one or two for each puppy. These are to dry the puppies and to stimulate their hearts and breathing.