I just finished Uncertainty: Einstein, Heisenberg, Bohr, and the Struggle for the Soul of Science by David Lindley, a concise and accessible, indeed enjoyable, account of Quantum Theory's antecedents and of the ferment surrounding its development and early years. Lindley brings the personalities involved to life, not only those of the subtitle but also Max Born, Erwin Schrodinger and others. To my mind, he doesn't give Paul Dirac nearly enough credit or space. On the other hand, apart from Bohr he concentrates primarily on German speaking scientists.
As well as a useful history on its own account, Uncertainty serves as a helpful backgrounder for the interested layman whose grasp on the actual Science and Math of Quantum Mechanics is a bit vague. Thanks to Lindley's book, I have returned to The Strangest Man with some hope of being able to follow Dirac's discoveries.