Recording your screen, to give or get help
Are you aware of the various alternatives for creating a visual recording of your screen with voice over or other callouts on the screen? These tools can be great for creating either brief overviews of how to do something, or longer tutorials. I've even used them to send to a customer support rep for a product having a problem, and they've said it was very helpful to have such a real view of what I'm seeing.
Rather than create a list of them here, I'll point you to a nice article that does that, offering a nice intro on each, and discusses the concept of using screencasts to help others. Indeed, it's called:
Screencasting to help your mom
http://labnol.blogspot.com/2005/05/screencasting-to-help-your-mom.html
I'm a longtime fan of Camtasia myself. Sure, it's not free, but you often get what you pay for. One tool that the articles doesn't mention, which is free for Powerpoint users, is Microsoft Producer : http://www.microsoft.com/windows/windowsmedia/technologies/producer.mspx
While the sites for each of the product linked to in that article will have resources to help you get started, here is a nice O'Reilly article on the general idea of creating screencasts: http://www.oreillynet.com/pub/a/network/2005/06/13/primetime.html