Jean Fouquet, peintre et enlumineur du XVe siecle is an exquisite French-language exhibition devoted to the fifteenth-century painter Jean Fouquet. Fouquet--known, among other things, as the painter of (possibly) the first stand-alone self-portrait--is best remembered for the Melun Diptych, now split between two museums. His illuminations include the Book of Hours of Étienne Chevalier and contributions to the Book of Hours of Simon de Varie, among others.
Chartres: Cathedral of Notre-Dame offers photographs, diagrams, antique prints, and maps of Chartres Cathedral. And that's not the only virtual Chartres site: there's a tour courtesy of San Jose SU and a more elaborate tour (requires Quicktime) offered by the Art History department at Ithaca College. Among other things, Great Buildings features some 3D models (additional, albeit free, software required to view). Speaking of virtual experiences, you can walk the Chartres labyrinth (see here for a more technical description). And don't forget video, including this National Geographic short on the cathedral's architecture; you can also listen to the bells.
Memoirs of Phillipe de Commynes. A first-hand account of the 15th-century military and diplomatic struggle between Louis XI of France, a master of intrigue, and his most powerful rival, Charles the Bold, Duke of Burgundy. "At that time the subjects of the house of Burgundy were very rich because of the long peace which they had enjoyed and the great moderation of the prince under whom they lived, who taxed his subjects little. It seems to me that then his territories could well have been described as the Promised Land, more so than any others on earth. They were overflowing with wealth and they had a peace which they have not since experienced during the last twenty-three years. ... But today I do not know in this world a people so desolate, and I fear that the sins of the time of their prosperity have brought them their present adversity; most of all because they did not recognize that all these favours came from God who distributes them as it pleases him."
In the South of France you'll find the fortified city of Carcassonne, a UNESCO World Heritage site, and a classic example of the medieval fortified city. Built upon the ruins of forts that predate Christianity, Carcassonne is one of the most photogenic places I've ever seen, never more so than on Bastille Day, when the city sets the night sky ablaze. A full gallery of Carcassonne fireworks can be found here.
Images of medieval architecture. A great site put together by Alison Stones, Professor of History of Art and Architecture at the University of Pittsburgh. There are two large gazetteers, one for Britain, and one for France. Besides photos, there are many plans, sketches and elevation drawings, which help to give an idea of the sheer scale of gothic cathedrals such as the cathedral of Saint-Étienne at Bourges (scroll down for the human figures at the bottom).