Need Help, Omerta and Godfather, please help...

Here's what is a matter. In my English 11 class, were are required to do a Historical Investigation Research paper on a Famous writer. I chose Mario Puzo. But the problem i am having is that i am confused about Puzo. Heres why:

What are the real reason's why he wrote the Godfather and Omerta. I know the Godfather was to put food on the table, but come on there has to be a real reason why he wrote it. I mean you just dont come up with a story and write it, unless he was that good. Is there a theme within these stories? What point's is he trying to make?

2nd: Could someone possible Analysis both books for me, and give theme's that are related to both books. I am so confused.

Any insight on both books, wat people got from the books anything will be a great help. I read GF and Omerta, so my mind is little blank. I really need some help. Any help you guys can give is appeicated. Also if you know of any sites that have good things about Puzo, example, critic's talking about his works, or anything.

Thank you,
Chris

I think at the highest level, Puzo is demonstrating the conflict between the glamourous side of the mafia (money, loyalty, power) and the price paid to achieve it in The Godfather.

The Godfather is a collection of every great Mafia story packed into one. Or so I think. For instance, THe opening wedding is based off of Joe Clombo's wedding. Coincidentally Al Martino(the dude that played Johnny Fontane) sang at Joe Colombo's wedding. Johnny Fontane is supposed to be Frank Sinatra.
As far as theme goes, Mario Puzo said it was about a king and three sons. Michael was the one that wasn't going to get mixed up in the family afairs. Sonny was the one eager for the throne, and Fredo was the idiot son who just kind of existed. If you're looking for character changes like I have to do when I do a literary analysis, Michael was a patriot and a law abiding citizen. The turning point, the murder of Solozzo. Afterward he slowly gre colder, until he met Apollonia. After her death he grew relatively loveless and even colder. By the end of the book, he was all business and was no longer the innocent kid his father once wanted him to be.