Links for Technical Drawing Applications
Listed in order of usefulness.

Art Studio Chalkboard - my personal favorite

The Figure Drawing Lab - "This site is devoted to better understanding of the elements that make up the human figure and how to better portray them. It is intended as a resource for artists and art students who work with the human form."

DrawSpace.com - Excellent drawing lessons.  Registration is free.

ColorMatters - "The concept of color can be approached from several disciplines: physiology, psychology, philosophy, and art. This web site provides some starting points for an exploration of color."

Art-Wow - beginning drawing lessons, classic and contemporary

Drawing/Sketching - "Learn the basics of drawing and sketching by trying some of these great online tutorials and resources."