Pet food regulation
The US Food and Drug Administration Center for Veterinary Medicine (FDA-CVM) regulates pet food manufacturers on a national level. They have the authority to inspect foods, fine manufacturers, and recall diets if they are not up to standard. They have FAQs for pet owners and provide links to outside resources as well.
Veterinary medical resources
Veterinary specialty resources
The American College of Veterinary Dermatology (ACVD) is a group of board-certified veterinary dermatologists who specialize in disorders of the skin, nails, ears, and hair. They have resources for pet owners, including their "Find a dermatologist" directory, as well as short articles on common skin conditions.
The Veterinary Oral Health Council (VOHC) is sponsored by the AVDC. It authorizes the use of its seal of approval on certain products (toothpastes, treats, diets, etc.) that are proven to be effective in preventing dental disease. Check out their "Accepted Products" page for a list of these products.
VetSpecialists.com is a go-to resource for any other veterinary specialties you don't see above. It is a great place to learn more about the many different specialties in veterinary medicine. They also have articles for pet owners on many subjects, including cardiology, neurology, oncology, and internal medicine.
Feeding Raven Doodles provides these resources to pet owners for additional reading and educational material. None of these resources should be used to substitute proper veterinary care, diagnosis, or treatment.