'Octupus' by Claire Sterling about the long reach of the Sicillian mafia. From the 80's, I think.

'Mob Nemisis' by an FBI agent (Don Griffin?) who worked against the mafia in several cities. The section about the Cleveland mafia removes all vestiges of the 'dignity' in being a Man of Respect in novel and film. It reveals an absolutely hellish way of life.

Excellent Cadavers is a good book.

'The Last Days of the Sicillians' is pretty good but maybe too detailed, about the investigation and evenual arrest of Sal Catalano, Casesar Bonventre, Baldo Amato and numerous other 'zips' affiliated with the Bonnano Family.