I offer you a room in a good conditioned house near the Helsinki city center.
The area has been built in 1950's and it is very peaceful. There is a tram and bus stop near by and you can take almost any bus or tram to city center and the trip takes only 15-20 minutes.
Also city bike stations are very near. It takes only about 15 to go by bike to the city center.
I am an experienced traveller myself and i gladly share to you my tips about travelling in Finland. Welcome!