Equipment for recording video:
Equipment for recording audio:
For free audio conversion software for PC and Mac see: http://blogs.ucl.ac.uk/ele/2015/03/16/need-to-convert-wav-files-to-mp3/
Free options for recording audio on a Mac:
Free options for recording audio on a PC:
For either of these options to be able to capture a Windows computer's native sound output (eg Skype, Youtube videos etc - not external audio such as a microphone) the soundcard will need to be configured accordingly. Windows soundcards vary from machine to machine, but a fairly comprehensive set of instructions for configuring them can be found on a dedicated Audacity hardware configuration page.
Options for recording Skype calls on a PC:
If you want to learn to how to create videos for your courses, please download the guide Producing your own teaching and learning videos