Types of Visual Art
Certain things - actually, lots of things - in the history of art aren't confined to one period or style. ("Painting" comes immediately to mind.) This section is to help you find what you need to know about each.
History of Oil Paint
Nice article detailing paint itself, including what was used before oils, and those who developed and then refined the medium.
A Brief History of Printmaking
This article explains the differences between pre- and post-Gutenberg printmaking, as well as those between woodcuts, etchings and engravings. From the Printmakers Guild.
The Joy of Shards Mosaics Resource
Rod Humby has assembled the world's best mosaic site here! There are virtual tours of famous and historical mosaics, a gallery in five parts, lovely images and a wealth of how-to information, should you be inspired to create your own. Of special note is his well-written and illustrated (with digital images) piece "The History of Mosaic Art". Enjoy!
Stained Glass Photography
The photography at this site is incredible. Neil Ralley is on a mission to make historic stained glass designs available for public viewing. To that end, he currently has over 300 images uploaded, including works of William Morris and Tiffany Studios. Please check out his cards, too - they're ideal for Christmas, and proceeds help support Neil's stained glass preservation work.
A History of Photography
Subtitled "From its beginnings till the 1920s", this site covers just that. Included is information on museums of photography, a bibliography, and a section on significant people.