I have an assignment to write a story based upon crime. I'm doing mine on the Mafia but I haven't got much knowledge on the subject. Anyone know a site I'd be able to research it or someone knowing a lot of information on it available to educate me on the basics?

You'll find bits and pieces on many sites but I don't know of one that'll do just what you want. And, yes, I did do the search for exactly the same reason you're doing it. Or course, that was in 2010 and much more is available now.

Or, you could read The Godfather by Mario Puzo or, for sheer fantasy and entertainment, Greenmantle by Charles de Lint. Both will give you a feel for the subject and, particularly in Puzo's case, both seem very authentic.