Cam Studio is free no idea how good. http://camstudio.org/
Getting everyone using the same Quality/Compression standard will be needed for consistency. I would use an H.264 in a MP4 wrapper for HD video.
Might be good to make a bumper video/Intro video that has a MangoLassi logo and some other stuff and then we could have a slide that the person doing the screen capture puts up right after that (similar styling) with the Title of the training, and the presenters name.
I would break anything over 30min into parts.