are good reading. I see somebody has already answered you fairly well here:http://archiver.rootsweb.com/th/read/ITALIAN-NOBILITY/2005-0...
What were the names of your immigrant ancestors? You should be able to find them in immigration records (ellis island, possibly) etc, and work out where in Sicily they were located, and then go back to find them in Italian records for that place. (The LDS church have filmed civil registration records for many locations)