To provide some background, can you post a little about why we would need this. I think I know where you're coming from. Just to clarify for others. :)

Recently there have been a few posts on the forum that might not be, shall we say, "beneficial" for the community. Additionally, there have been a few forum posts and "tutorials" that seem to be little more than an advert for the submitter's products. (I know I link to a lot of other sites/products, but I'm not doing it for profit for myself!)
It would be good to know where we all stand when it comes to what is acceptable when it comes to user submitted content on the site.

I posted on one of the threads in question, and please let me be clear: I'm totally against someone posting that kind of thread. Most of this persons threads are nothing but intentionally inflammatory. But at the same time, it has more to do with the phrasing of the post, in my mind, and the intent behind the post. So as we set guidelines (if we do) lets make sure that intent is the primary factor in enforcement. Then the question becomes, do we want moderators determining intent, or the community at large by using a flag system?

As far as the product review section: My opinion is that it is perfectly acceptable for someone to post their product on there, as long as they don't review it themselves, or anyone affiliated with the business aspects of the product reviews it. The product itself should also in some fashion serve the users of this community. That doesn't seem to be an issue.

Also, it seems like personal respect should factor into this. There's a huge difference between discussing the biblical viability of a certain lifestyle and attacking someone personally, and I don't think the line is very ambiguous.

So, as far as forum posts go, and comments in general, I would say personal respect should be paramount, and we should be very careful defining someone's biblical view on sin as a lack of personal respect for another forum member, or a group of people.

Blessings,
Tony

Paul Boag posted some thoughts on moderation in audio form: "Should Communities Be Moderated?", which could be used as a starting point.

Also from Paul, this time in his full length podcasts (a little old now):
Podcast 58: Community websites Part 1
Podcast 59: Community websites Part 2

These might also give some tips (but I've not actually listened to them since they came out, so I can only guess at the moment! I'm pretty sure they'll be good though).