Here are some resources for presentations. These are not geared toward education but very useful anyway.
Presentation Zen by Garr Reynolds along with his great website at http://www.garrreynolds.com/
Non-Designer’s Presentation Book by Robin Williams (not the actor)
While I hate to say how many slides or words per slide you should have, Guy Kawasaki has a unique perspective due to a medical condition: http://blog.guykawasaki.com/2005/12/the_102030_rule.html#axzz1mTkHNJHz
And remember, “Don’t put your talk on your slides, and you won’t have to read them!” Robin Williams