itch.io

There are various libraries in the game: The closest one in Tarkas is accessible if you are part of the mage guild. Go to the library in the basement and do your research there (there is a shining spot in the library). If you are a student at the magic academy, there is also a library there (ground floor, top-left corner). There are others, but these are probably the easiest ones to access. I might have to add one you can access just by paying a fee, for those that don't want to progress any of the secondary paths.