American Institute of Graphic Arts
American Institute of Graphic Arts (AIGA) is a well-known professional association for graphic designers.
"AIGA's purpose is to further excellence in design as a broadly defined discipline, strategic tool for business and cultural force. AIGA is a professional association committed to stimulating thinking about design through the exchange of ideas and information, the encouragement of critical analysis and research and the advancement of education and ethical practice" according to it's mission statement.
Among the resources for business to be found on AIGA's web site is: A Client's Guide to Design: How to get the most out of the process.