A video editing software that can be downloaded for free is Microsoft Movie Maker. An explanation of how to use can be found at http://www.microsoft.com/windowsxp/using/moviemaker/default.mspx
Microsoft Producer allows you to incorporate audio and video with PowerPoint. It is free and has a plug in for PowerPoint. It can be downloaded at http://www.microsoft.com/downloads/en/details.aspx?familyid=1b3c76d5-fc75-4f99-94bc-784919468e73&displaylang=en
Both of these programs are useful for enhancing online course content.