I have been leading an established family type guild for a few months now. We are fairly relaxed and only raid occasionally. It does not cost me any money and very little time. I'd say on average less then one hour a week looking up information on raids for epics, DON progression, planar progression. I have only been playing the game for 1 year and don't know very about progression, raid's, epic's and such, so it's a learning experience for me.
As far as rules, I would just say that whatever rules you want, you have to find other people willling to abide by them. Be willing to negotiate and flexible or you may have trouble adding to your guild.
Summary : It really involves what you want to put into it and what you want to do with it. I would guess that recruiting could be time consuming, depending on how selective you are. Preparing for raids, hunts, and specific kills will depend on how much you already know and how much you have to discover.
Added: BTW I do not maintain a website, would guess that seting a site up would require time, but maintance would depend a lot.