OFA's Recommended Breeding Principals for Hip Dysplasia
Breed normals to normals
Breed normals with normal ancestry
Breed normals from litters (brothers/sisters) with a low incidence of HD
Select a sire that produces a low incidence of HD
Replace dogs with dogs that are better than the breed average
The bolded statements require that you know the health testing results of dogs in your dog's pedigree meaning parents, grand parents, great grand parents. It also requires that you know the status of siblings.
For more detailed information about breeding away from inherited disease when only phenotypic testing is available, read this article http://www.offa.org/hovanart.pdf
Responsible breeders, breed dogs from known pedigrees with generations of health testing in order to reduce risk of producing disease.
Just because someone produces puppies and sells them does not make them responsible.