This paper presents the methodology and the results of the development of a set of age-centered research-based web design guidelines. An initial set of guidelines was first developed through careful literature review of the HCI & Aging literature. Then a series of classification methods (card sorting, affinity diagrams) were employed as a means for obtaining a revised and more robust classified set of guidelines. Finally the revised set of guidelines and the original set were tested through their application to a number of age-related websites.