If you want a good insight and truly cultured look into Sicily's Mafia read "Midnight in Sicily" by Peter Robb I think. Theres a great chapter on Naples too, including the Cammora and the N'drangheta. Theres a lot of names thrown about in it and I could understand it to be a little confusing but if you've got a basic bit of backround on it, it will be a good read for you.

So die all who betray Giuliano