Dealing with aggressive posters
If someone acts aggressively towards you on the forums or, in your opinion, isn't playing by the rules, then don't overreact. If they really are going too far, then it's more likely he/she will suffer any consequences. If you lose control, the chance of continuing a sensible discussion is severely decreased. The thread often deteriorates into an flame war which is not in anyone's interest.
New Thread
Before you open a new thread, ask yourself these questions:
1) Am I in the correct forum? Does my topic belong in the Non-BB forum or, perhaps, the Help forum?
2) Is there already a thread about my topic?
It's always better to post in an existing thread than open a new topic about the same subject. This shows you've made the effort to look for an answer yourself and also read the opinions of other users. Duplicate threads will be shut very quickly.
If you're sure you're in the right place, then you can open a thread.
Titles
Use explanatory and understandable titles for your topics!
The thread title is a very useful way of getting the attention of other managers using 50 characters or less. Don't waste your title on throwaway general subject lines such as "help me!" ( or worse "HELP ME !!!!!!!"). Don't use this space to express the size of your pain; use it for something more useful.
If you have more than one question, comment or suggestion then write them together in one post. There's nothing more irritating than clicking through a couple of click fire threads by a single user. It shows you haven't thought about what you want to say before you start writing.
Make it easy to answer your post.
It is important to express your question or opinion in a clear and structured way. If that's too much effort for you then it's usually too much effort for someone to try and understand what you want. Spend a little time re-reading your post. You don't have to be too formal with your language, but questions and comments should be written with some precision. This is an indication that you're interested and paying attention.
Some people that have understood that being unfriendly and arrogant on the forums is a bad thing often choose the exact opposite. "I know, I'm a stupid, pathetic, n00b loser, but .. ". This isn't amusing and even less helpful.
Generally, if your post is unclear then you won't get a sensible answer.
--Thanks to BB-Oxidus for most of this!--