I'm new to this mmo thing. I understand there are three main factions that are fighting for control of Cyrodill, and there are the guilds that have made an appearance in almost every tes game, including the Db, thieves guild, mages ect....but say I have a bunch of friends who wanted to form our own guild, with its own banner/emblem ect.., is this possible? I also understand that you can't make your own guild hall unless you forcefully take residence in a location. This would really help me better understand the game. Thanks

Yes, player-made guilds are in the game. There are many guild that have already been formed on multiple sites, such as Tamriel Foundry. The ZOS team has also mentioned guilds capturing forts in the PvP area Cyrodiil and using it as an HQ for their guild. We don't know everything about the guild system though.

thank you very much this is very good news to me. Capturing forts and using them as HQ's is something that I could really look forward too.