My Maya API videos will soon be released. I've gotten word that they will be open to the public very shortly. The Maya API series is about 6 hours worth of video covering several topics from creating commands, contexts, locators, deformers, file translators, and dependency graph nodes to working with callbacks, multi-threading, attribute editor templates, and distributing your plug-ins.
I've also created an Applied 3d Math video series. This series is a little over an hour and covers how to actually use 3d math with practical examples. This isn't your typical how-to-multiply-matrices math tutorial. I don't even go over how to multiply matrices! The focus of this series is how you can apply 3d math in your day-to-day work.
Stay tuned for the actual release. It should just be a matter of days.