AppraiserCentral.com
Find a licensed real estate appraiser in every state. Includes appraiser message board and real estate news.
http://www.appraisercentral.com/

International Society of Appraisers (ISA)
Offers a comprehensive professional development program designed to build and enhance performance in the area of personal property appraisal practice as well as specialty studies.
http://www.isa-appraisers.org/