Kim,I would caution against icons.  When I was a graduate student in library school, I took a class in usability. We discussed the drawbacks of using icons because users interpret them differently.  This would probably be a problem you might encounter since you are dealing with a user population that has diverse cultures. If the lab manual is going to be completely digital, then I suggest you consider creating a website for it and using the fundamental principles of usability as you go along (http://www.usability.gov/).    Here is a website that was developed with such principles: http://lib.asu.edu/ .  We read a paper about its development in class.  As you can see, the use of icons is minimal, while text is prominent throughout.


Karen Salazar