I am traveling with 2 Families to Pompeii from Rome, would it be best to take a train or rent one vehicle (if possible)? In addition, I have tried to contact Gaetano Manfredi via telephone and have had no luck. Would anybody have an update number or email address?
I suggest that you take the train. It's very easy. Transfer at Naples. My family and friend group had 12 people. There are guides in front of the ticket booth, or you can, if you wish, rent an audio guide.
You do NOT "need" a tour company or service to do this trip for you. It is so SUPER SIMPLE. Take the Eurostar (fast train) from Rome Termini to Naples, transfer to local commuter train Circumvesuviana and head for Pompeii Scavi. The train lets you off at the Pompeii Scavii station and you will walk to the clearly marked entrance in about 5 minutes.
If you want a tour guide there will be plenty of them there waiting and asking if you want to hire them. You can also just rent an audioguide or just take your Rick Steves book.
Pompeii was interesting, but I personally would not do a daytrip from Rome because it's just too far. Most of your time for that day is spent on the train. A much more enjoyable option would be to spend a couple of nights in Sorrento which is at the end of the Circumvesuviana line. It's about a 15 minute train ride from Sorrento to Pompeii. Sorrento is a beautiful seaside town with many hotels built on the jagged cliffs. Very relaxing base for Pompeii.