I use a high-end professional screen capture and editing program, so that will not fit your needs. But there is a good, relatively low cost, product on the market that does a good job of capturing screen video. It is called Camtasia from Tech Smith. Here is their web site: http://www.techsmith.com/
Their Camtasia Studio costs about $300 but it is the best low cost solution that I am familiar with. There are probably others out there and a lot of times you will find software like this bundled with computer video cards.
As far as video format, I would recommend recording your videos as .avi files. This is an old standard and most video players can play this type of movie. I use avi myself because you can easily record larger videos, where some of the more modern video formats limit you to a specific screen size or resolution.
Also, to learn all there is to learn, just go to Google and do some searches. Try "video capture" "screen capture" "avi", I know you will think of some more.
