I've just finished re-reading South African photographer Obie Oberholzer's book 'Obie'. For some moronic reason it's only available in South Africa, but my contacts smuggled a copy out for me last year
I'm currently also re-reading Nassim Nicholas Taleb's 'Skin in the Game', and reading for the first time Susan Sontag's 'On Photography', which my younger son gave me for Christmas
Next up is John Berger's 'Understanding a Photograph', which my son also gave me, and Roger Ballen's 'Ballenesque' which is winging it's way to me even as I write