Smithsonian Institution
Smithsonian Learning Lab: Landscape Painting
A Smithsonian website plus lesson plans on the art of landscape painting. Includes details on landscape painting techniques to create the illusion of depth and space as well as information on four landscape artists.
Art Cyclopedia
Artcyclopedia: Chronological Listing of Landscape Painters
ArtCyclopedia's chronological list of landscape painters from the 16th thru the 20th centuries. There are links to the artists' biography and works.