I recommend Graham Farmelo's 2009 biography of Dirac, The Strangest Man.

http://www.guardian.co.uk/science/2009/apr/02/paul-dirac-str...

I once started a physics degree at Bristol, where Dirac was born and raised, and the department made a big show of 'their' man. The house he grew up in is a few minutes' walk from the department, and has a blue plaque indicating its status. It was some years before I discovered that Dirac had never been in the physics department at all, but in fact studied electrical engineering, before entering Cambridge, where he flourished as a physicist.