If I had to choose just one, which book should I get?
The Good Rat - Jimmy Breslin
Al D'Arco - Jerry Capeci
Five Families - Selwyn Raab
Mob Star - Jerry Capeci
Five Families, for sure. It gives you a crash course on the NYC mob from pre-Commission (although there are other books that go into greater detail there such as Critchley's
The Origin of Organized Crime in America: The New York City Mafia, 1891-1931 and Mike Dash's
The First Family: Terror, Extortion, Revenge, Murder and The Birth of the American Mafia) all the way to post-911.
I'd actually get Capeci's other book on Gotti, called
Gotti: Rise and Fall. It only covers up until Gotti's imprisonment but that's about all you need anyway. It goes into much more detail than
Mob Star.