I think you’re usually appointed and it’s unpaid. I was a moderator on another site and it was because the site owner asked me if I wanted to be one and I said “yes”. :)
On most websites, being an moderator is unpaid. Here, it is unpaid. We work from wherever we feel like it—I have it on good authority there is a great deal of iPhone moderation going on, but I’ve never been able to handle that.
However, on websites where the position is a paid one, you will need experience in community building. Since there are so many unpaid moderator positions, they would expect you to come into it with a good deal of experience already.
One of the most important pre-requisites is a picture of yourself with shark-fin goggles in a blue bikini. A lot of patience and to get asked by the founders.
Nobody asked me, and that tells me that not only are the founders smart, but they are a pretty damn good judge of character. And that’s not bad for a couple of young whippersnappers named Bendrew.