I would check with the Italian side, here is a link that may help: http://www.poliziadistato.it/articolo/view/10930/
I could be wrong but if you are living in the U.S. now, your wife may need to apply for a certain type of visa before going to Italy. You will need to have your marriage certificate translated into Italian by the Italian consulate in the U.S.
I am a U.S. citizen married to an Italian citizen and we are now living in Spain. I first received permanent residence in Italy and then after we decided to move and I have now received residence in Spain. I know when I moved to Spain, I needed to be coming straight from Italy with residence there, otherwise they would need me to have a visa for Spain issued in the U.S. so I am wondering if you are going to run into the same problem in Italy.
Do you have a job in Italy? As it is not the country that you have citizenship in… you may have to have a job and be paying into social services before they let your wife have residence and work. The way I saw it was… as a Spanish citizen, your wife has a right to live with you in Spain if you are working or not, but if you want to live in Italy, that right is not the same. I could be wrong but this was my experience. Also be aware that it is a long process that could take up to 6 months or longer. We got married in March and I still did not have my identity card when we moved to Spain in November!
Hope that helps and if you have questions about the Italian way of things, let me know! Which city in Italy are you thinking cause that will make a difference?