If you're interested in Finnish Folklore, this book is a good place to start. It gives more of a general overview of many topics in folklore. If you're interesyed in more specific details about the areas discussed (such as different ethnic groups in Finland, historical agrarian society, legends, folktales, riddles and jokes to name a few) then you might be some what disappointed. There are quite a few examples of different genres of folklore and they were actually collected in Finland. The examples are given both in Finnish and in English.
The organization of the book is confusing at times, and some topics are discussed are listed in the reference section even though there is very little information on that page.