--Nutrical for Puppies
--Quality Kibble (at least some of what the breeder is feeding, even if you want to change, that way you make the change gradually and not upset their tummies)
--Water & food bowls
--crate
--several soft blankets
--bed
--x-pen or plastic play yard
--pee pads
--TOYS, preferably some made for teething puppies
--brush & comb
--harnesses, leash & a coupler so you can walk them together easier
--Make sure you have a themometer that you can dedicate to the pups
--A nice mild, quality shampoo and conditioner (Espree, Minksheen, etc....)
--A carrier that both can fit in to take to vet and other trips
--A couple of books on Yorkies and puppie training (you can check these out at the library and then find the ones you want to buy for reference).
I think that could get you started. Then you will find dozens of other wonderful products as you continue yorkie ownership. Sometimes I think I spend more on them than I do on myself! But then, they are more fun!