I have read about Norway in a Nutshell, but are there any day trips to Sognefjorden from Bergen via the fjord? Would you recommend spending the night in a fjord town or just a day trip?
If you have a car (from your other question) you can drive out to Vangnes in a couple or three hours with really good scenery along the way and about zip for traffic. The NiN deal can also done as an out-and-back from Bergen - - that's about the best way to actually get down into the fiords in that area.
Spend the night! I spent one night in Balestrand and one night in Solvorn. Both were beautiful places. Balestrand is much easier to get to than Solvorn. I used public transportation in Norway. I found the cost of renting a car to be outrageous. Bergen is ok but it rains a lot (and did while I was in town). There was still snow on the ground in some places when I did the Nutshell route and it was the end of June so plan accordingly.