Although his political blog is often a place for sniping and argumentative comments (following perhaps in the style of the posts), this is a very clear piece of work. It sets out in a friendly (as friendly as the blog gets), conversational, tone just what is and isn't allowed in the comments on order-order.com.
While every point isn't transferable to all blogs, I for example love a long an detailed response to any post on sites I run, it's useful to read it and to think about how comments add value to a site — or even possibly detract. If it's a personal blog, it's very much "your gaff, your rules" and if you set them out no-one can argue. [link]