(I also found it easier to record the onscreen action separate from the narration and then merge them into a single project. TWO - I came to the conclusion that you need to have a moderately strong ability to capture separate audio narration and add it to a video project. ONE - It didn't have the ability to do the sort of advanced annotations that I think a good video tutorial should have to keep people's interest.
I started out using ACDSee Video Studio 2, which I quite liked, for an inexpensive basic consumer level video editor, but it had two major shortcomings. You really need a video editor of some sort to increase edited quality. It is kinda, sorta possible, but the quality is 'kinda, sorta' primitive. I am trying to produce photographic post processing tutorials and I started out trying to use just Snagit.