There's much more to being a guild leader than been the head of a bunch of merry men (and women). Even if you've been a guild leader in other games, you may be better off learning a little bit about AoC before starting up a new guild or taking over an older guild. This guide (on the native blog site) has a lot of links back to the forums, resource sites, and other blogs, hopefully providing a useful resource for new guild leaders.
Here's some things to think about as you ponder starting a guild.