References for different genres.

As a writer, I think it's also very important to be a reader as well. I'm well read in sci-fi/fantasy/thriller novels, but at the moment I have quiet a bit of modern day mafia/mobster flair in my book. I've seen it done on screen many times, but if anyone could recommend literature pertaining to the subject, I'd be very grateful!

Also, I figured this could be a beneficial to other people looking for similar recommendations - perhaps just for different genres.

If you're referring to mafia related literature I highly recommend The Godfather by Mario Puzo. Excellent book and great research about the mafia.

Read The Sicilian by Puzo too. In fact, I'd recommend reading all of Puzo's work, since they're all mostly to do with the Mafia.

But if you want a no-holds-barred account of how Mafioso tactics are used in pretty much all terrorist organisations, read Paul Williams' Crime Wars. It centres mostly around the IRA and different Irish terrorist factions, but it is a real-life account of what goes on behind the scenes.