NCREIF
Nat'l Council of Real Estate Investment Fiduciaries represents investment managers, accountants, appraisers and other real estate professionals. http://www.ncreif.com/
Appraisal Institute
Find a qualified appraiser or read about what they do, when and why you need an appraisal, and how to get a copy of your appraisal report.
Foundation of Real Estate Appraisers
FREA offers benefits and education to appraisers. Formed in response to Title XI of the Financial Institutions Reform Enforcement Act of 1989.
American Society of Appraisers
The nation's oldest multidisciplinary professional appraisal society. Free, but registration is required.