This is three ideas of using video combined into one example.

1.  Using screen capture video with voiceover

Screen capture software can be installed as software locally or used as an online service, such as http://screenr.com.  Free versions usually create videos of up to 5 minutes.

Here's an example of using screen video to support Year 1 student's use of Blackboard to submit Assignments (in this case the  slightly tricky example of cutting and pasting a url into the text box for submission).

Link to video at screenr  http://screenr.com/MIH 

How it looks in Blackboard (won't work as video - just an image)

2. Using video animation

Xtranormal is a video animation software/service that lets you create animation (with 2 characters and various sets) from your own scripts and directions.  This is rather long so you won't want to watch too much of it.

3. Editing the url to jump to a specified point in a youtube video.

Helen Keegan gave me this nifty tip that lets you cut to the chase of a youtube video by adding #t=5m35s to jump to 5 mins 35 seconds, for example

http://www.youtube.com/watch?v=uilkFoe4hQo#t=5m35s