I've recently finished reading Envisioning Information
and it's a book I highly recommend no matter how you're presenting information. Now, as far as presentations are concerned, the most valuable chapter is that discussing color. There is a lot of the book that advocates creating easy to read, yet condense tables and other displays of information. However, such displays are not appropriate for slides because the audience would be spending most of their efforts reading instead of listening. The valuable lesson, though, is condensing the message into a simple and easy to read display.
