The town library of Kaskinen is situated at the main square
See the opening hours here
There is a nice selection of books in English and DVDs. There is a special section of films for children. The library memership is free. If the library is closed when you want to return the material, you can pass it through the mailbox at the front door.
There is also free computer access, and an open WIFI that you can access also outdoors at the square and the Guest Harbour area.