I'm interested in reading some of Mr. Puzo's books and I'm just wondering, before I begin, which order I should read them in? Are they a series with returning characters or is it just a matter of personal opinion? Thanks ahead of time to anyone who's willing to help me out here!

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!

The Sicilian is basically about Turi Guliannos fight against the friends of the friends and local Mafia cheifs. It takes place in Sicily ( of course ), and Michael Corleone was in it. Michael was in Sicily, escaping from USA, because of the murder of a police man and the turk. Michaels job was to transport Turi Gulianno into America.
That's all I can say, I dont want to spoil it for everyone.

So, my little opinion is to read the GF before the Sicilian.

Yeah although three books, "The Godfather", "The Last Don" and "Omerta" are called Mario Puzo's Mafia Trilogy the only two books that are somewhat connected are "The Sicilian" and "The Godfather". I've been reading the books backwards kinda. From newest to oldest. Omerta, The Family, The Last Don, the Godfather.