Resource are scarce.

Here are some resources that can provide some great insights. The author (Amjad Jamoukha) is a close relative of mine. Look into all his writings. He is probably one of the most known Circassian Historians/Authors. 

https://www.circassianworld.com/pdf/Circassian_Customs_and_Traditions.pdf

http://jaimoukha.synthasite.com/resources/Circassian%20Religion.pdf

https://en.wikipedia.org/wiki/Amjad_Jaimoukha