I am trying to figure out how to take a screenshot that shows the cursor in the screenshot image. Neither Command-Shift-3 or Command-Shift-4 do this. Any help would be appreciated.
Grab will allow you to do that. It's already on your system, just search for it with Spotlight. In it's preferences, you can even specify which cursor you'd like to use, including the spinning beach ball, the copying symbol, etc.