i started with Omerta and then went on to the Godfather and next i think i'll read Fools Die. I dont know if their a seris i think Mike Corleone is in the Sicilian but i'm not totally sure. you could always start with the first one he wrote and finish with his last (Omerta). i think his first was the Dark Arena but i'm not too sure but you have to read his books! Mario Puzo is great!