Jordan Rudess Online Conservatory has introduced a set of video tutorials on modular synthesis.
The series features Richard Lainhart using a modular analog synthesizer to show and explain the basic concepts and techniques of analog synthesis for modern electronic musicians. The nine progressive lessons start with the very basics of sound and synthesis and cover descriptions of the standard analog synth modules, what they do and how they sound, and how to connect them all together.
The series costs $25 to dowload. The first video is available for free.
More information is available at the JROC site.