Start with high-confidence christian rituals & practice books, then narrow by subgenre or adjacent topics.
A History of God
Karen Armstrong
Accompany Them With Singing--the Christian Funeral
Thomas G. Long
A Manual for Acolytes
Dennis G. Michno
A Working Manual for Altar Guilds
Dorothy C. Diggs
A Celtic Eucharist
Brendan O'Malley, Brendan O'Malley
Eternity Today, Vol. 1
Martin Connell
The Advent Jesse Tree
Dean Lambert Smith