Resources on usability, user interface, interaction, design, design patterns, data visualization and more:

Edward Tufte

Inventor of sparklines.
http://www.edwardtufte.com/tufte/

Books/Essays:

• The Visual Display of Quantitative Information
• Envisioning Information
• Visual Explanations: Images and Quantities, Evidence and Narrative
• Beautiful Evidence
• The Cognitive Style of Powerpoint

Robert Spence