Good luck and Congrats for the puppies that are coming.
I also have puppies coming ...Sept 30th.
This is the 1st for Lily and the 4th time I'll be whelping a litter.
I usually let the mother do everything except caring during whelping.
I am right their, just incase.
Have a heating pad on low under a few towels to keep the newborns warm, while the mother is still whelping the other puppies.
It takes a while for the puppies to dry and in the mean time the mother is whelping other puppies. So you don't want the puppies to get cold.
I have experienced this even if it's a nice warm day, they still get cold.
Good luck