Taxis

Only use official Taxis, there will be touts around the airports and train stations offering taxis services, ignore them or you will be ripped off, their cheap quote will increase when you arrive as they will add on luggage etc. Official taxis are white with the city logo on the side, even in these insist they use the meter. If you are traveling outside the city beware if they try and charge you for the return trip, they say it is because they will not get a fare back to the city, however the tariff officially increases outside of the city to allow for this so they have already received more. This tariff changes when crossing the GRA which is the Rome ring road, ensure they do not change it earlier. To and from the airports there is a fixed rate for up to 4 people and their luggage to anywhere within the old city walls of 40 Euro from Fiumicino and 30 Euro from Ciampino, if it is outside the old city walls then the meter applies.

Buses & Metro

There is a standard fare on the buses and metro of 1 Euro, this entitles you to travel in one direction for up to 75 minutes using the metro and buses. The tickets can be bought at tabacci and newsstands around Rome, you cannot buy them on the buses. You need to validate the ticket in the machines on the buses or when you go through the turnstiles on the metro. You can get daily tickets and weekly tickets.

Trains

Trains are quite cheap in Italy although they get more expensive the more luxurious they get. For example a stopping train from Rome to Naples would costs 10.50 Euro and take around 2 1/2 hours, a Eurostar non stop costs 33 Euro and takes around 1 1/2 hours. However the less you pay the more likely you will have to stand at least some of the way, the Eurostars are reserved seats. Locally around Rome you buy a ticket for a certain distance, so a 20 Km ticket can be used for travel from any station in Lazio and you can travel up to 20 Km in one direction. The ticket is live when you put it in to one of the yellow machines at the station to get it stamped. You can also write the start station on the ticket and the date and time to validate it as well, this is because quite often the stamping machines don’t work. You can get daily tickets and weekly tickets for use on local trains.
You can get train information from TrenItalia