The Mail Artisans International League -- Thousands of weave styles, including tutorials on the basics.
CG Mail -- Step by step graphic chainmail tutorials. Highly recommended!
Fyre and Ice Chainmaille -- Jewelry designs and samples of basic weaves.
Apocalypse Creations -- Maille clothing, including some more risque designs.
Venom's Pit -- Excellent sizing charts.
Wyrmwire -- A master mailler with incredible talent out of Las Vegas, goes to several of the RenFaires in California and Nevada.