Generally, you shall have a clear understanding of the users
here.
Know when it's a joke, a sarcasm or a clear flame and insult.
You can decide on your own rules, since it's your own forum. Since
this is a crapping forum, the rules shall be rather lax but in my
opinion, you shall only take control when there's clear flaming or
insults flying around.
I've been a moderator before (somewhere else) and know how hard it
is to decide the course of action against a user. 
