We arrive into rome and will stay a few nights but then wanted to move onto sorrento region. What's the best way to get there and any suggestions of places to stay which would not be too expensive!!?

My favorite way is to take a train from Rome that stops at Mergellina station in Naples, then take the bus or taxi to the port then take a hydrofoil to Sorrento.

I like the hydrofoil idea! However, if you want to stay on land, take a Trenitalia train to Naples (www.trenitalia.com/en/index.html for timetables and fares) and the private Circumvesuviana train from Naples to Sorrento (http://tinyurl.com/cgu3n for timetables).

would it be worth our while to stay in naples just for a night or just give it a miss?

TimS has given you good advice especially considering that you want to visit Pompeii.
As far as Naples, it depends on your interests and your time. You haven't told us what your itinerary is.
While Naples has its pluses, I would rank it below Rome, Florence, Venice, and even the Amalfi Coast as a must do. I stayed in Naples for two days and it was plenty. I enjoyed the food and the Archaeological Museum.

Hi Typ - There is also a direct daily bus service to Sorrento from Rome (- operator: Marozzi).

Departures are from Roma Tiburtina.
Fare: approx. € 16. Journey time: approx. 4 hrs

http://www.marozzivt.it/

You can visit Naples very easily as a day-trip from Sorrento - by train or hydrofoil. That would be more convenient than a one-night stopover IMO.

Hope this helps ...

Steve