I was just wondering if it would be possible to volunteer at a library? If so, what sort of duties would I be doing?
First of all: if one cannot speak Finnish moderately well, there are quite few jobs at the library available. The customers have the right to get service on their own language.
There are some duties, where the fluent Finnish is not so necessary - like putting the returned books back to shelves and other technical jobs -, but the main question is, if the library really needs that kind of help. I would say, that many public libraries do not necessarily want volunteered people, unless they have some kind of experience with the library material or with customer services.
But in the end everything depends on the local circumstances and the thoughts of the chief librarian. You just got to visit one of them to know, if working in the library would be possible and what the duties might be :)