Excellent introduction to the Renaissance movements by About Guide to Art History, Shelley Esaak.
Useful bio and overview of Palladio's style, works and influence, from your About.com Guide to Architecture, Jackie Craven.
Also offering a biography of the influential architect and a timeline of Venetian history, this site focuses on five of Palladio's surviving mansions, providing a photo and architectural information on each.
Nine thumbnails of the exquisite palace lead to larger photos. Part of A Digitial Archive of European Architecture by Professor Jeffrey Howe at Boston College.
This introduction to the history of art through the Middle Ages is followed by segments on early and high Renaissance art, with pages on Masaccio, da Vinci and Raphael to illustrate the developing movement. Nicely presented with some fine images at Wesleyan College.