I am looking for a Yorkshire Terrier or Chiwawa for studding, how should i go about lokking for them?

You are either planning two litters at once or you don't care what you mate your bitch with, you also cannot even spell one of the breeds so all in all you don't really seem to have anything like the knowledge to commence breeding.  If you dog is a registered pedigree you could begin showing it to see if it has any merit to a breeding program if you are unable to show ask the bitches breeder to assess her assuming the breeder was a responsible and preferably showing one otherwise the breed club can put you in touch with someone suitable and take it from there.  If you were considering cross breeding I doubt you will receive any assistance from this board as this type of breeding is generally regarding as unethical.

I think that you also need to find out more information about the breeds you are asking about.  The least you should know is how to spell the breed.  Better not say anymore as I think I've said enough already.