Business Classics

Porter, M. E. Competitive Strategy: Techniques for Analyzing Industries and Competitors . New York: Free Press, 1980.
You can't be an effective marketect or tarchitect without an understanding of strategy.

Mintzber, H., and J. B. Quinn. The Strategy ProcessConcepts and Contexts . Englewood Cliffs, NJ: Prentice Hall, 1992.
Ditto.