Ah well, it's a strange genre.
apparently the base name for this sort of accidental amateur detective story is "cozy mystery" - a typical subgenre is "british cozy mysteries" (that is, based in an english or scottish village, although I have seen some based in London) but "paranormal cozy mysteries" are another example where the characters are witches, elves or other supernatural races, often living covertly in human society....
Given the latter is a genre of webcomic I quite enjoy, I decided to give the books a try....
Come to think of it, Harry Potter would probably qualify too (and also sorta under the whole "british residential school" genre too)