Having puppies is what dogs do, so just let nature take it's course. Make sure the mother dog has plenty of water, and that she feels safe. If the puppies don't nurse you can get milk from the local vet.
The puppies will need to be in a draft free room with a tempature at 70-80 degrees. Create a bed for your puppies with a box and some towels. Keep a newspaper on the ground near their bed for them to use as a "bathroom" as they won't be able to travel too far at first.
The biggest thing to remember is that they are your dog's puppies. You will need to start feeding them wet food at about 4 weeks or so. You should be aware that the puppies need to be cared for by their mother until they are 6-8 weeks old.
Let the mother do most of the taking care of them. You will need to make sure that the family is comfortable. She will need milk when she is nursing, so that her puppies can get calcium that they need. Be sure not to take the puppies away from the mother until the are somewhere between 6-8 weeks.
First off is it a confirmed pregnancy? Gestation for dogs is about 52 days. You will know when she is going into labor when her temp. drops below 100 degrees. I suggest reading on the web on "whelping" procedures because they vary by breed. Good Luck.