Players are strongly encouraged to help develop the world, even if only by one bit at a time. The process is pretty simple: post your idea as a proposal. The judges then take a look at it, and discuss, suggest changes, and vote. If it's voted up, it becomes added to the wiki.
I just took up doing the same for Cortesia (although getting a level 1 game in the water took priority). I did a quick wiki check: there is scant little else outside of the page about here and a handful of characters that have her listed as their Deity. With Cortesia, I found an adventure that made reference to an abandoned temple that should at least be mentioned.
As for characters who worship the deity in question, you can cull their backgrounds for ideas. I pulled the idea that Cortesia apparently has a bit of a structure for helping raise/educate children built in. It appears in more than one background. Just an example from recent history.
Excellent, I'll be fishing through the character archives to see if anyone is a follower. I'm thinking along the lines that the church had a school of monks dedicated to Amenthia who provided the defense of the temple. I thought a sect of divine monks, dedicated to unarmed combat and healing arts with the temple would be interesting, but I wanted to be ok if that was something that would work. I added the weapons training aspect of my character to different trainers in Tritower (since I'm going for master of many styles, it fits).