Look for breeders that will welcome you into their home so you can see exactly how they are raising and caring for their Yorkies.
Also do some research online, ask for referrals, check references. YT is a good place to learn about Yorkies as well as YTCA too.
A good breeder will check your references, your vet references and other things about you. You also should do the same with the breeder.
You do not HAVE to get AKC registration.
AKC does not automatically mean you will be getting a well bred puppy. There are TONS of puppymills that have AKC registered litters. So don't go by that as your only marker.
AKC, CKC, or any registration is only as good as the breeder behind it.
Good luck in your search
and take your time to find a breeder you trust, it will be worth the effort