Overview of social psychology, including biases and group behavior:

• Social Psychology course by Wesleyan University

Psychology of influence

• Influence by Robert Cialdini

Analytical thinking

• The Art of Doing Science and Engineering by Richard W. Hamming
• The Feynman Lectures on Physics
• Godel, Escher, Bach by Douglas Hofstadter

General strategy

• Good Strategy, Bad Strategy by Richard P. Rumelt