We rescued Tiara at 6weeks 5 days old. She is a spunky 10 week old today.
She was very nippy when we got her home. We followed what everyone else said about bite inhibition. The concept is very basic but it is very important that you follow through with it. Teaching just not to bite will not be enough. They need to know that human flesh is fragile and their teeth can harm. As soon as she nips, we YELP! and brush her away gently. Immediately when she did it again we YELPED! and got up abruptly and walked away for like 30 sec. If this continued longer we would give her a 20 sec time out alone in the bathroom. Not the crate as we did not want her to associate it with something bad.
This goes on almost constantly till this day, although I would say she has improved dramatically over the past 3 weeks. No longer does it hurt when she nips and the frequency is down to maybe 40% still nipping.
The most trouble is with my 8 year old son, she sees him as a play toy and is obsessed with nipping him. My wife and 11 year old son are improving very nicely.
It takes time and consistency but eventually they do get it.
As far as all the talk about bringing them home too early, don't get all freaked out about it. I did. But After researching and training with her, I feel she will turn out just fine if not better. Yes it is best for the pup to remain with the mother up until 8-12 weeks, but I have also read conflicting views on that as well.
Its freezing here in NJ and I took her outside at 6weeks 5 days every hour to pee in the middle of the night when it was 20 degrees. She is almost 11 weeks and healthy as an Ox.
Just use common sense and everything will be just fine.