Cheap way to trip from Venice to Florence and Florence to Rome? :)

The cheapest way would be by regional train but you'll spend hours doing that. You can buy tickets ahead of time and get really deep discounts but those tickets are not changeable or refundable so be very sure of your travel plans when you book them.

Donna

Thanks again Donna
How to book this kind of ticket? Is special train? which website?

Trenitalia.com is the website, you can book up to 119 days in advance and get the cheapest possible fares (supereconomy) but these are highly restrictive and don't allow changes once you purchase them. You will get an eticket within a minute or two of booking.

Trenitalia often runs 2 for 1 weekend specials but these are usually for roundtrip tickets.

Also check Italo for trains on those routes. Private competitor, but nice high-speed trains, competative rates.

Welcome to this forum! I'm sure you'll find many knowledgeable people happy to share their information and experiences. You don't indicate whether you will be traveling soon, or well into the future, or what part of the world you will be traveling from. In any case, it sounds like a good place for you to start would be with a good travel book that covers the parts of Italy that most interest you, evidently the "Big 3" of Rome, Florence and Venice. The Rick Steves Italy Book is a very useful book, as it not only describes all the major sites in those three and other locations, but also covers a lot of logistical items like various forms of transportation, hotels, restaurants, culture, shopping, etc. With limited travel days available, you will certainly find that these three really wonderful cities each offer much more than you can possibly experience in a short visit, plus other very interesting nearby excursions. How you plan the number of days and experiences you choose in each location will depend a lot on your own interests, such as history, art, food and wine, music, big cities v. smaller towns, hiking, interaction with local people, etc., and also your own budget and preferred pace of travel. Some people like to go, go, go and cover as much as they can fit into the time, while others preferences (or stamina) lead them to visit fewer towns and sites in a more leisurely way. Also, every time you move from one lodging and town to another, eats up a half day or more, even if the the transportation itself only takes a couple of hours.

The cheapest way would obviously be walking. I do happen to know a fellow that walked from Rome to Florence (he was fleeing Nazis during WW II so it was not easy, and it took five days or so). And you know a fellow that did Florence to Rome and return.

Seriously speaking, the cheapest way is by fast train if you reserve one of the relatively few non-changeable tickets that are offered well in advance. You have to adapt your plans to availability of tickets, if any. And think that your time may be as valuable as your money. If you have plenty of time you can travel on the cheap, but if your time is limited a fast train ticket is a way to maximize its use.

Check out Italo. Great service, clean and secure lounges, helpful staff, great website, easy to purchase tickets, fast trains, lots of travel time options. They travel to all the cities you mention, with some station options within those cities (for example Rome) that are not provided by Trenitalia. Some fare types allow the holder to change departure time for a small fee, even for reduced fare tickets purchased in advance.