有關北歐自由行...

I have lived in Finland for some time. I can give you some suggestion for your trip in Finland. (Sorry I don't know much about the other Scandinavian countries)

For your travel in Finland, don't spend much time in the city. I think one day in Helsinki is already enough coz there are only a few churches worth sightseeing. Insetad, you must go to visit the central/northern Finland where you can swin in the lake and walk in the forest (wild blueberry picking). Of course, you should also try sauna. I dun like Finnish food much and they are very expensive, even for shopping in supermarket. To rent a summer cottage, you can try the travel agency in Helsinki.

Apart from central Finland, other places worth going are Rovaniemi (Santa Claus village), Turku and Aland. Tavelling by train is quite convenient in Finland. Of course, it would be much more convenient if you can rent a car.

Hope this can help a bit.