11. Know the difference between informative, interesting, and insightful. Informative means that the poster is giving facts about the topic, typically from referenced, outside sources. Informative posts should not contain opinions. Interesting posts contain personal anecdotes about the topic or suggestions for other uses of the ideas described. Insightful posts present well-reasoned opinions about the topic at hand.
12. Don't waste time modding down posts that are below +3. Most people won't see the posts so you're not substantially helping editorially which is the purpose of the moderation system. If you think a post urgently needs downward moderation, relax, some one else will certainly do it.
13. Finally, if it made you laugh, it's funny. If it makes fun of chinese/black/jewish/french/christian/islamic/hindu/whatever people, who cares-- if you're easily offended, internet message boards are not the place for you. If it's funny and offensive, it's still funny. Don't be like this asshole.