The train to Soller runs from the train station just across from the Plaza Espania in Palma....get the bus into the main bus station in Palma, take a left out of the bus station and walk down almost to the end of the street with the park on your left. Just before you reach the wide main road you will see the station on your right. There are two types of train, one is the normal tourist train and the other is the "panorama", which in fact just means that it stops 1/2 way to give you a panoramic view.
http://www.sollernet.com/trendesoller/en1.html
The train is very popular and consequently can be very busy, so unless you are there early to grab a good seat it can be difficult to actually see very much on the trip, which is through some lovely Mallorcan countryside.
At Soller you can get the tram right outside the train station and go down to Puerto Soller, a lovely little resort which is one of the most visited and most photographed spots in Mallorca. Soller itself is a very pleasant old town, the shops close from around 2pm till 4:30 so it can be quiet.
As a day out it is very pleasant and a must-do-once while in Mallorca, although I would not rank it as an unforgetable experience.
