I've been working my way through this excellent and thorough podcast from Harvard University's distance learning program. If you ever wanted someone to walk you through basic computer science principles step-by-step, this is the podcast you have been looking for.
From their site:
"This course is all about understanding: understanding what's going on inside your computer when you flip on the switch, why tech support has you constantly rebooting your computer, how everything you do on the Internet can be watched by others, and how your computer can become infected with a worm just by turning it on. In this course we demystify computers and the Internet, along with their jargon, so that students understand not only what they can do with each but also how it all works and why. Students leave this course armed with a new vocabulary and equipped for further exploration of computers and the Internet. Topics include hardware, software, the Internet, multimedia, security, website development, programming, and dotcoms."
If you are like me - and your computer knowledge has come piecemeal through necessity and curiousity - you will enjoy seeing familiar terms and concepts broken-down and explained in a classroom setting. Here's a direct link to the RSS feed and the iTunes podcast feed. Harvard broadcasts an mpeg video version along with mp3s in both feeds.