My closest ancestors (grandparents and great grandparents) are from Poland, Lithuania, Britain, and Ireland. I have started in these places to begin my investigation into who my ancestors were before their cultures and spirituality were Christianized. For others who are on the journey of discovering themselves in this way, here are the resources I have found to be the most informative specific to my heritage. I will add more resources to this list as I find them.
RESOURCES
Slavic Ancestry
Searching For The Slavic Soul
Slavic Paganism: Creations Stories, Deities, Influences, Spirituality, Folklore, & Baba Yaga
GRMEK, M. D. (1959). Ancient Slavic Medicine. Journal of the History of Medicine and Allied Sciences, 14(1), 18–40. http://www.jstor.org/stable/24620921
Bienkowska, D. (1973). History of Polish Folklore Research: 1945-70. Journal of the Folklore Institute, 10(3), 197–211. https://doi.org/10.2307/3814196
Slavic Paganism: Creations Stories, Deities, Influences, Spirituality, Folklore, & Baba Yaga
GRMEK, M. D. (1959). Ancient Slavic Medicine. Journal of the History of Medicine and Allied Sciences, 14(1), 18–40. http://www.jstor.org/stable/24620921
Bienkowska, D. (1973). History of Polish Folklore Research: 1945-70. Journal of the Folklore Institute, 10(3), 197–211. https://doi.org/10.2307/3814196