When I produce an Emacs screencast it takes four or five hours. That is after producing a handful that I’ve published and a few that I threw away. Over time I expect the process to get shorter but it is still pretty long.
There are a lot of Emacs screencasters out there. In addition to the tips there:
How long do you spend producing your screencasts and what are you tips and tricks to get the most production value in the least time?