Ken Molay, who writes a blog about webinar development (The webinar blog), has produced a series of 12 short instruction videos giving advice on how to plan and run effective webinars. His main focus is on producing webinars for the business world but most of the tips are equally valid for educators. The most important advice is careful preparation and ensuring that all speakers have the best possible audio and video quality.
The videos can be easily accessed from the YouTube channel, Webinar Basics. Here is the introduction video.
Effective Webinars 