I don't know much about RP guilds, but if you're interested in the UESP's guild, @baratron is the leader of our PC NA branch, info hereCurragraigue wrote: »If anyone is going to know re TES Lore talk it would be @Enodoc
If you don't mind forum discussions you could check out this one as well
http://en.uesp.net/wiki/Main_Page