Our family will be traveling to Rome in June with our 2 daughters (23 & 21) and will have one day to take a side trip out of Rome. We are very interested in the Tuscan/Umbria regions but don't want too much traveling involved. Can anyone recommend a day trip that will give us a taste of the Italian countryside? And whether we should rent a car to do this?

You can easily take the train to Assissi or Orvieto. We are planning on going to Orvieto during our trip to Rome next week. I would recommend taking the train instead of driving especially if you are staying in Rome. Rome is dreadful with a car. Trains in Italy are wonderful.

If your day trip is not on a weekend, I'd recommend Orvieto. It's easy to access by train. Lovely hill-top town; one of the absolute most beautiful duomos in the world, without all the crowds and brouhaha; good food; and excellent gelaterie to boot!

I agree with Orvieto.
Another option is train to Chiusi and rent a car there.

The ride from Rome to Orvieto is only an hour on the fast train, a little longer on the local. But the ride itself is not particularly beautiful; to truly get an idea of the rural areas you should rent a car in Chiusi as mentioned above by Jabez.

I know you asked about Tuscany/Umbria but in June you could also consider a seaside town like Sperlonga or Nettuno for a day out of the big city.

A trip north to Florence would be a great way to spend the day.

Or a trip south to Pompeii / Sorrento area.

With 21 & a 23 year old daughters, you might want to seriously consider a day trip to Florence and give them "just a taste" of the Italian Renaissance by visiting the incomparable "David" by Michelangelo in the Galleria dell "Accademia and then a stroll over to Piazza della Signoria, for a visit to the art of the Italian masters in the Uffizi museum. After a 1/2 day of culture, spend the last 3 hours shopping for jewerly on Ponte Vecchio or Florentine leather goods in shops across the Ponte Vecchio. This is an relaxing one and a half hour trip on the Euro Star express from the Rome Termini train station. You can leave at 8:00 a.m. and be back by 6:00 p.m.
You are not going to see much of the Tuscan countryside from the windows of a fast train to Florence or Orvieto. If the trip to Florence is not for you, you might want to consider a bus day tour to Assisi/Orvieto. These are slower with more opportunity to experience the "feel" of the countryside with stops in Assisi and/or Orvieto. You can check out some of these tours at: www.greenlinetours.com or www.vastours.it . If these are not the correct web sites, simply enter Green Line or Vast Tours or Carrani Tours, Rome and hit search and you should get several sites to search. These bus tours will pick you up at the hotel and drop you back off there, but remember these are long (12 hour bus trips). Of course, if money is not an object, you could hire a private driver to give your family a tour of the same places.
Regardless of what you do have a great trip and eat lots and lots and lots of gelato......
Lee
Lee

Thank you for your great ideas! Now I need to decide between Orvieto and Florence. One of my daughter's roommates spent last summer in Florence and came back with a suitcase of new shoes so she would vote for that. I have learned so much from these forums, they are addictive...just as I'm sure the gelato will be! Risab-I would love to hear about your experience in Orvieto once you return.