JDJarvis over at Aeons & Augauries brought my attention to this post by JB and confirmed I wasn't the only one thinking on this subject.
In my early days of gaming religion played a large part in the game. The church and the state were the 2 most powerful entities affecting the world through smaller groups like Assassins Guilds and what not.
In notes for a sub-campaign in my own Forsaken Souls : StoneGate Sagas religion is set to play a large part in the proceedings. So I started looking for source material and even though I have lots of historical matter to draw from (I have studied The Crusades since I was a child and always fascinated by the Knights Templar-who were all but eradicated on my birth date in 1307) but noticed a lack of game related material.
This then is what I have found and I hope it helps others.
For me it started over at Inkwell Ideas with the excellent Worldbuilding: Fantasy Religion Design Guide and Worldbuilding: Fantasy Religion Design Example and his list of resources to which I added:
“Choir Practice at the First Church of Lawful Evil (Orthodox) the Ramifications of Alignment” Dragon #24
“Of the Gods” Dragon #29
"So Many Gods, So Little Time" Dragon #140
“Made-To-Order-Clerical Orders” Dragon #142
"Gods, Myth and Faith" Dragon #258
"Gotta Have Faith, Part 1" Dragon #283
"Gotta Have Faith, Part 2" Dragon #284
And finally, although not a strict cleric sub-class the Necromancer covered in the White Dwarf #35 is an interesting read.
Any information readers have please feel free to leave in comments. I will be collecting for the follow up post to this one any material GMs / Designers can use in their own settings. I am particularly interested in obscure ancient religions and their rights and rituals.