Ok, so I have a video to edit due for class tomorrow. My question is this:

How do you edit the clip as it is playing?

For example, in my video, we show two different experiments. I want to draw an arrow pointing to the first experiment saying that it is "Experiment #1", and draw another arrow to the second expriment saying that it is "Experiment #2".

I want the arrows to be shown for about 3 seconds as the clip is playing.

Is there any way to do this on Windows MovieMaker? If I can't figure this out, I was thinking that I'd just take a screenshot of the scene and freeze it and edit the .jpg and do it that way.

Yes, I have searched for this, but I'm probably not using the right "media jargon".

Thanks in advance.