FRAPS is a program that runs in the background. It captures the screen when running, and saves the video when you stop it.
Run FRAPS, then press the F9 key, that starts the vid, another press of F9 will end the capture.
Then edit the raw video with MS Movie maker to add titles, edit sequences etc.
Have a play round, you will discover all the features.
When happy, open a YouTube account, and upload some vids. Remember not to make them too long, maybe 1 or 2 minutes.