An overview of trolls from the oldest records to the current day.
Some of the oldest must be deciphered. "Troll" in words often just means magic -- a "troll-woman" is a witch. "Given to the trolls" means "killed." Past that, there are legends, such as trolls caught by sunlight through the cleverness of some hero -- they may become landmarks and so useful instead of a danger to travelers. Or build churches, though you may have to guess their names to escape paying severely for it. And a law prohibits sitting outside to summon trolls.
Then fairy tales and illustrators, and when "troll" came into English -- mid nineteenth century -- on the heels of fairy tale collections. And modern day fantasy treatments, and troll dolls, and the various metaphorical uses of the modern day.
Weak in a few points -- he interprets tales that trolls can eat those who go out at night or grow fat on food cooked on Sunday as trolls enforcing human prohibitions, not that violations create a weakness they can exploit -- but a good overview.