The Appraisal Foundation has produced a short (2-page) brochure (download it here:
PERSONAL PROPERTY APPRAISERS AND YOU), that very succinctly and clearly offers the general public and others who recommend appraisers to individuals (librarians, museum curators, bank trust officers, attorneys, insurance companies, etc.) advice on what qualifications appraisers must have and how to find appropriate specialist appraisers.