You will want to weigh the puppies at least once a day until they double their birth weight. This is one of the best ways to get a jump on any problems that may be starting. Some way to identify each puppy. You need to be able to tell who's who, so you can keep track of everybody's progress. There are lots of ways to do this.
Some people mark each puppy differently.
I have heard of breeders using everything from nail polish to clipping fur from different areas of the body. Others use some type of collar. I used different color ric-rac for awhile, but it can get expensive. These are inexpensive and can be knotted to fit well. They are strips of heavy paper with adhesive on one end.