In the left column you can find a list of all the cities in Italy whose cities has Metro, Subway, tramway or urban trains.
On each tab you will find information about their metro system of each city: zone maps, length, line numbers, stations schedules, fares, payment systems accepted, owner and operator, average and max speed, date of opening, link to the official site and more, as this guide of subways is being updated constantly.
To zoom in the map, you just have to click on it. In some tabs, you can also find metro maps available for downloading.