Since I've received all the useful info for a very enjoyable trip, I'd like to share with you my experience: We didn't take any trip through the ship.
Stavanger - took the Rodne boat to Lysefjord. We reserved through their site, and paid on arrival.
Olden - took the local bus to Briksdale glacier, and then trolleys. The bus is located on the main road, about half a mile from the pier, in front of the main shopping center.
Geiranger - took the local bus to mount Dalsnibba, right on the pier, tickets at the tourist office. Get there quickly, not enough places... Amazing views.
Bergen - took the funicular to Mount Floyen, walked back down. Amazing views. You can buy tickets at the tourrist info only if you want return tickets. So we stood in a long line for tickets for about 45 minutes, while groups had priority...
I'll be happy to reply to further questions, and thanks again to this forum for providing priceless tips for individuals who like to make their own plans... Daniela