Spend some time on Robin Good's Presentation Tools site - it's worth it.
Andrew Abela: Advanced Presentations by Design: Creating Communication that Drives Action
Describes the 10-step Extreme Presentation method and the research underlying it.
Garr Reynolds: Presentation Zen
Great book on Ballroom style presentations (*****)
Rick Altman: Why Most PowerPoint Presentations Suck
Comprehensive, rich, full of good ideas and helpful advice (*****)
Edward R. Tufte: Beautiful Evidence
The latest volume from the master (*****)
Gene Zelazny: Say It With Charts
A Classic (*****)
Robert L. Harris: Information Graphics
The most comprehensive reference work on charts (*****)
Lori Silverman: Wake Me Up When the Data is Over
Using storytelling to drive business results (See my Sep 6 post) (*****)