Mom is probably doing a great job at cleaning up after them. If you think you have done a lot of newspaper changing up to now, get ready -- they will explode soon. Once you start weaning them, moms sometimes do not do as much on that end, and you got to stay on top of it because the puppies will learn some rather yucky habits.
As soon as the little poopers start really pooping in earnest and Mom goes on strike, they also will need toys to push around and play with. rubber toys and some stuffed toys, make sure they are safe though. A good rope toy, is a good thing too. They should play with you, and they should play with each other. And at this time, 3.5 -4 weeks you want to start bringing in people who they don't know -- not other dogs, just people and make sure they are very unlikely to have visited an high volume dog areas.
Playing audiobooks and the tv around the puppy also helps them get used to other types of voices and sounds. They should hear ordinary sounds like a dishwasher (I wish), etc. Take them to different surfaces, linoleum and carpet -- well, that is kind of up to you, take one pup at a time if you must.
Touch them all over, go through a calming routine with them where you touch their ears, and pet their backs, and rub their bellies and touch their tails and touch each toe.
Speaking of toes -- about now is time to start snipping the toe nails. cut the hooks off the ends. They should be transparent at this point and you should be able to see where the quick is. Don't hit the quick if at all possible. Each pup has 18 toenails, and when you have 10 puppies, you learn how to do them quickly and with little drama or trauma to you or the puppies. If you hit a quick, have stypic powder on hand.
Heidi Ho, Odie
Joy-Joy, Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.