Images and Video
User feedback suggests images help to make the tutorial more interesting
Clip art can be useful. See http://office.microsoft.com/clipart/
Images are available on the web or you may have your own. See the Technical Advisory Service for Images at
http://www.tasi.ac.uk/ for more information on how to find and use images as well as copyright and legal issues.
Video can also be added successfully. The BUFVC has a lot of useful information about finding, creating and using video clips. http://www.bufvc.ac.uk/
Consider using alt-text to make interactive exercises using pictures. See the examples section to see this in action.
To put your images next to the text and get a more attractive visual layout, insert a two column table to add a picture next to some text. Put the image in one cell and the text in the other. This page is an example of this technique