The Ghost of Raven Hill (Raven Hill Series #1) Book

The first of Emily Rodda's 30 book series (initially "Teen Power, Inc." but reprinted as "The Raven Hill Mysteries" introduces the six teenagers who, although very different, develop a friendship and respect as they investigate crimes. This one is told from the point of view of Liz, the kindly, creative member of the six-person gang (each book is told from one of the sextet's point of view) and it's quite an intriguing little mystery, with some great characters and a down-to-earth tone of voice. I loved this series as a kid, because it was clearly made for young but literate teens and never felt like it was playing to the cheap seats!