cubagirl, the fjords is a good one to try first. It was our first one and it won me over.
The advantage is it is only for a week, but long enough for you to work out whether you like it or not.
A typical week is : You board on Day 1 in the afternoon, Day 2 is spent at sea, Day 3 you are in Stavanger for the day; Day 4 you are in Olden; Day 5 you are in Flam for the day; Day 6 is spent in Bergen; Day 7 is a Sea day and Day 8 you are back in Southampton and get off after breakfast.
So you have four days out in different ports.
The scenery in Norway is awesome and the best way to explore the fjords is to sail down them.
Good luck.