So, Interactivity by Design is an older book and not specifically geared toward a slide show (it is focused on designing visually appealing e-learning). But it is well written with wonderful examples. I strongly recommend it if you are creating PowerPoint, Keynote or e-learning presentations/training.
Also, here are some great online resources;
Garr Reynolds Top Ten Slide Tips
Avoiding Death by PowerPoint
Four Ways to Improve a Presentation
How Cognitive Science Can Improve Your PowerPoint Presentation
Go over to Slide Share and search for "worlds best presentation" examples.
Here is one:
What resources do you use to improve your presentations and visual for e-learning?
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