Any suggestions on what is the best way to travel around the Dolomites? (I will be there for 3 days)
Which places/towns are worth seeing?

I can't compare other modes of transportation because we had a car and only used it. It certainly worked for us. We stayed in Bolzano which was charming and from there we drove the route to Nova Levante, S241. Just our luck it was heavy clouds the two days we were there, but what we saw was wonderful. In particular, the window boxes full of trailing flowers on the hotels. It seemed as though each was trying to outdo the other. There was some section of the road that were "white knuckle" moments but that just added to it.

Hi Nathalie - When are you going? Unless you are there in high season - when there are increased bus services and organised tours - you really need a car to see the best of the Dolomites.

Which places to see? The highlights of the Dolomites are the scenery rather than the towns. Head for the passes in the Sella area (- Val Gardena/Val Badia) or the Alpe di Siusi, take the lifts ... and walk

This is some of the most breathtaking scenery in Europe ...

A good base IMO is Ortisei. Alternatively the upper Val Badia ... or Castelrotto.

You might find these websites useful:
www.valgardena.it
http://www.altabadia.org/summer/default.asp?L=3&

Some views:
http://www.dolomitimeteo.com/gallery/index12.htm

Let me know if I can be of more help ...

Steve

As Steve James says the Dolomites are a place that responds best to a walking inspection. Leave your car and hike as much as possible!

Harzer

I agree you really want a car to see this area. Bolzano (Bozen) and Bressanone (Brixen) are both interesting places to stay.

Walking inspection? Hey Harzer - I like that. So THAT'S what I do

VT - Bolzano and Bressanone are certainly nice places to visit. But they are not in the Dolomites - so they don't make a good base IMO. Much better to be more central ...

Steve