I'd also look at the breeder and ask a lot of questions to see how knowledgeable they are on the breed. If I don't feel I can trust the breeder, I don't want to get a dog from them.
Cooper was 6 1/2 weeks when I took him home. I'm going to contradict what the Countess' mother said and say the breeder I got Cooper from didn't use age as a deciding factor in when he released pups but instead, he used weight and overall size. Of course, he wouldn't send a 2 week old pup home with you but some litters, he kept for 6 weeks and others, he kept 10-12, depending. So it varies from breeder to breeder on why they release pups - you might ask and see what the breeder tells you is their deciding factor.
I'd look at the cleanliness of the pup's environment, the interaction of the pups with each other and their mother if she's still kept with them, and just get a general feel of the place and the breeder. I go by instinct in these situations.
But definitely do your own "health check" on the pups. I would also ask if there was a health guarantee, a certificate of health from a vet, etc.
Good luck!!