"Aradia, Gospel of the Witches" by Charles Leland discusses one specific form of Italian folk magic, namely that of the Stregha. There is a lot of question as to whether the information in the book is historically accurate or not. However, it was certainly one of the sources that Gerald Gardner used when synthesizing what we know of as Wicca in the 1930's and 1940's. Just remember that Stregha and Wicca are two very, very different forms of religious Witchcraft.
If you want to read more on the history of Wicca and the folk traditions which were incorporated into it I would suggest "Triumph of the Moon" by Ronald Hutton and "Gerald Gardner and the Cauldron of Inspiration" by Philip Heselton.