I want to create a video tutorial showing screens as I move through the program. S/w ideas?

I have a couple of tutorials that I use to show seniors the steps to use in certain applications.
I would like to “film” (capture) them onto a DVD so they could be shown in our senior center library without me having to conduct the Help session.

1. Want to capture video of going through the screens
2. Would then like to add a voice-over.

I’m pretty good at business applications and even setting up networks. But have never done any video or audio “recording”.

Any software suggestions? Free or reasonable price, please.
I would really appreciate some guidance. A quick search left me overwhelmed with software options and I don’t know enough to evaluate them.