Every now and then, by total coincidence, I get a rash of identical requests from different people. For example, six different people asked me to make a guide for Danger on Deception Island all within a period of three days.
Recently, six or so people have asked me how I do video walkthroughs. So here's an explanation:
I don't use a video camera. I use a video capture program to record my computer screen. Video capture programs can record a specific section of your computer screen for a specific amount of time and turn that into a video file.
The specific program I use is called CamStudio. It doesn't work for everyone, I'm told, and so other people use programs like CaptureWiz, HyperCam and so on.
Got it? Cool. That's my bare bones explanation. There are plenty of videos on Youtube which will tell you how to work those programs and what their various features are. Check 'em out.