WebMuseum: Realism  
   Comprehensive and well organized site. A good source of reference covering artists and art movements ranging from Gothic and Renaissance to Impressionism and Pop.
   http://www.ibiblio.org/wm/paint/glo/realism/

Realism. Art Terms at Biddington's.  
   A brief discussion and illustration of realism in contemporary art.
   http://www.biddingtons.com/content/pedigreerealism.html