Forging relationships with galleries, art professionals and other collectors is key both to becoming educated about works of art and knowledgeable about the environment of buying and selling art. Join collectors' groups at museums to experience how museums themselves select works for purchase. Introduce yourself to curators and get to know more about the kind of art you are interested in.  Discover which galleries and dealers you can safely trust, but at the same time keep your own independence of mind by educating yourself through research at art-related libraries and on the Web and, most importantly, through looking at art in your local museums, galleries, and art shows. Some collectors advise beginning with smaller works,such as drawings or prints, by artists you like so as to understand their work process. Others advise focusing on a particular format or genre (such as landscapes or still-lifes) and then broadening out. Investing your time is as important as investing your money. You can  obtain help from dealers' organizations, such as the Art Dealers Association of America (ADAA), the Fine Art Dealers Association (FADA), and the Private Art Dealers Association (PADA). The major auction houses — Christie's and Sotheby's — also offer advice.

(Source: Intl Foundation for Art Research)