I think a big part of these interminable arguments about tabs is based on people using the same words to mean different things. In the following, I'm trying to avoid espousing my personal religion here, I just thought it would be good to try and explain the various sects. Anyway.
Puppies may be placed in new homes once they are eating well on their own. However, they will be better adjusted and make better pets by staying and interacting with littermates and the Mom-dog until they are at least eight weeks old--older generally is better.
While you can start taking puppies 5 or 6 weeks of age outside to encourage elimination, true housebreaking should start around 7 or 8 weeks. This is the age at which puppies are able to start understanding routines and rules, so the learning process is easier for them to comprehend.