There's been a recent flowering of scholarship in English about Zen and Buddhism that has dissolved the old tension between practitioner and academic. It used to be that meditators might be forgiven for wondering if scholarly studies on Zen were talking about the same thing they were practicing. But now much of the freshest and most insightful writing about Zen is coming from scholars, many of whom have their own direct experience of their subject. This work can help us better understand our inheritance and also demystify it, and that's a good thing; demystification clears the field in a way that makes the real mystery that meditation points to more apparent rather than less.

Steven Heine, Opening a Mountain: Koans of the Zen Masters (Oxford University Press, 2002)
A study that locates koans in a mythological and cultural context, particularly with respect to religious ritual and the supernatural, and then provides a wealth of scholarly commentary on sixty Chinese koans

Donald S. Lopez, Jr. Prisoners of Shangri-La: Tibetan Buddhism and the West (University of Chicago Press, 1998)
The West's romance with Buddhism is vividly and wittily chronicled in a book that's essential reading for anyone interested in how our projections influence even our search for a way to still them

John R. McRae, Seeing Through Zen: Encounter, Transformation, and Genealogy in Chinese Chan Buddhism (University of California Press, 2003)
This is one a number of recent reassessments of the mythology of lineage in Chinese Chan, and that section, as well as the deconstruction of the 'encounter dialogue', usually considered the core of Chan/Zen and the origin of the koan tradition, are illuminating

Bernard Faure, The Power of Denial: Buddhism, Purity, and Gender (Princeton University Press, 2003)
Well, the title says it all. A searing look at Zen attitudes towards women and the feminine

Brian A. Victoria, Zen at War (Weatherhill, 1997)
A groundbreaking and devastating study of the complicity of Zen Buddhists in the nationalist, imperialist, and militarist movements of modern Japan.