Geas

Is there any way to listen to a sermon and the like for gods that don't have an active priesthood / guild support? It's hard to get info IC about say, Zhakrin I imagine, unless you are lucky enough to meet the right character. Either that or happen to have access to the right books, but for the common layman it seems hard to get much info in game. Most of it is OOC.
(webpage, wiki, helpfiles, etc.)

NPC Priests don't give sermons right?

No, they don't give sermons, even though it might be nice to have them do it automatically every day or two. Would be a good way to make followers meet up.

But sermons don't really teach a lot about gods, because it's usually either the default sermon for all deities, or it's a player-submitted one.