
A person advertising in the Free ads may be a responsible breeder, but when you say breeds regualarly (by which I take it they advertise often) then I would be very careful of buying a pup from someone that is breeding often. Most people who bred for the love and betterment of their individual breed will breed not very often. I would say a litter or a couple of litters some years.
Get in touch with your local Breed Society, and they will usually know who the rogues are and who is reputable.