Here are some programs I use to make very simple podcasts
Perios Time Lapse Photography is a freeware program I use to control my web cam when making podcasts http://perios.ic.cz/
Audacity is a freeware audio recorder and editor http://download.cnet.com/Audacity/3000-2170_4-10058117.html
Interwrite also has a screen capture utility that will allow you to record your computer screen.
The attachments below are ones I have made for extra practice or for maths competitions, homework etc. (please check them before using)