There are heaps of programs out there that you can use to record the goings on on your screen (called a screencast). These programs are sometimes attached to your computer’s webcam but sometimes they aren’t. Nevertheless, they all work pretty much the same (by clicking record to record, stop to stop and so on) so really, it is just a matter of getting one and trying it out.
On a Tablet
All of the tablet PCs have CyberLink YouCam on them which has the option of recording your screen by clicking the ‘Desktop’ option.
Not on a tablet
If you haven’t got a tablet then you will need to download a program to make your screencasts for you. I recommend CamStudio as it is free and provides you with lots of options. You can download it by clicking this link. Once you have downloaded it you can check out one of the many online tutorials such as this one on YouTube. It’s great (sniff) because it … ummm … tells you how to set it up too. Or you can just play around with it.
Have fun with it!