To successfully transmit spatial information, maps must be well-designed. There exists a canon of design guidelines for paper maps, but a concise compilation of guidelines for the design of web maps is currently not available. This chapter contributes to this need by providing recommendations and guidelines specific to the design of web maps. Topics include the choice of a viewing technology; the influence of limited screen resolution and anti-aliasing; minimum dimensions and distances for map features; the generalization of information density and geometry; problems of screen typography; color rendition and; the design of user-friendly navigation tools. Some of these guidelines are based on the authors’ mapping experiences, while others were deducted from the observation of Internet user behavior or compiled from selected sources.