Step 1: Flame Wars
By-and-large, the trouble with The Internet, and forums in particular, is that everyone gets to be anonymous. That essentially gives them free reign to be as snooty and argumentative as they like.
A troll posts deliberately controversial or annoying messages for the specific purpose of getting a rise out of people and initiating a hate-filled and overly-argumentative thread. The appropriate course of action is simply not to respond. Don't feed the troll.
Step 2: Godwin's Law
Godwin's Law states that â€œas an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one. What that means in real terms is that sooner or later someone involved in a forum argument will be likened to a Nazi, or displaying Hitler-like tendencies. Please note that if you're the one invoking Godwin's Law and likening someone to a Nazi, you've immediately lost the argument because it's such a lame-a** low blow.
Step 3: Fanboys
Approximately 99.9% of all online forums are based around videogames. Sadly, there are several members of the videogame community who have such an overly-fanatical devotion to their particular console that they're somehow incapable of admitting any other system might have good features too. They're best ignored, because Fanboys are basically a special subset of Troll, and as such are all Nazis and/ or Hitler.
Step 4: Teenagers
Sadly, teenagers are allowed on The Internet too. They have funny ways of spelling and don't understand that proper grownups don't want to put up with their pubescent attempts at humour. There's nothing you can do about Teenagers on The Internet, you'll just have to learn to circumnavigate them. Not all teenagers are evil, mind. Just most of them.
Step 5: Post Count
Every time you post, your post count goes up by one. Some people seem to think that the higher the post count, the more worthy and valuable they are to society at large. Frankly, the exact opposite seems to be the case; posting just to up your count is insanely annoying, so make sure all your messages add to a discussion in some way. If you're replying in a thread, make sure what you're writing is funny, interesting or funny and interesting. "yeh i agree lol" is not, in any way, shape or form, a valid reply, ever.
Step 6: Respect the Admins
It's their website, and they can do whatever the hell they like with it. You're a guest, and hassling them about how they run things is akin to going round your Auntie's house and curling one out in her tea-pot.
Step 7: DON'T USE ALL CAPS IN YOUR POST
EVER. "Shouting" through the written word is pointless and annoying, clearly.
Step 8: Lurk Before Posting
Don't just jump in to the forums spouting off reams and reams your amazing knowledge of the intricacies of World of Warcraft. In Binary.
Lurk around a bit first and read some threads to see whether or not that's even remotely the sort of thing people there would be interested in.
Step 9: Keep On Topic
If a thread's all about how amazing a new 2D Sonic the Hedgehog game would be, don't derail it and start talking about something else entirely, like Chun Li's thighs. Make a new thread if you absolutely must.
Step 10: Picture Etiquette
Don't post massive pictures that are wider than most peoples' screens. What's more, don't post massive pictures of filthy grotty porn or anything in case people are at work. Not even the most ardent heterosexual likes looking at boobies when sat near their boss. It's enough to put them off for life.
Step 11: NSFW
What's more, make sure you mark any risqué links as Not Safe For Work, just in case, and make sure doing so is in keeping with the forum's tone. By and large, just remember to be excellent to each other. Be all civil and pleasant. Keep your tongue firmly in your cheek and get a nice thick skin.
BUT WAIT, THERE'S MORE! It turns out there's even more annoying stuff people do that we simply couldn't squeeze into the film...
Step 12: Signatures
...should be small and tasteful. Massive graphics plugging something you're selling are a right royal no-no. Text is very much preferable.
Step 13: Avatars
Your profile pic is how people picture you, so choose something good-looking, funny or interesting. Pretty much anything goes, just make sure it isn't ugly or annoying and fits with the tone of the forum.
Step 14: Gravedigging
Old threads are old for a reason, and that reason is that noone's interested in discussing that anymore. Unless you've got an outrageously good reason to do so, leave dead threads to Rest in Peace.
Step 15: Drama
Used properly, The Internet can be a tool for good. If used for overblown, melodramatic weepy Emo nonsense, it's ruined and needs to be scrubbed clean. Learn to relax and take everything in your stride. No one's on The Internet to get all stressed and angsty, we're all just here for a good time. So leave all your haughty drivel at the door.
Step 16: Smilies
If used sparingly a smiley can emphasise a point: sarcasm comes across extremely poorly in forums â€“ almost dangerously so. A quick winky will sort that. Reams and reams of extravagant animated smileys performing all manner of wacky acts are annoying, and are the sort of thing your mum would do, were she able to use a computer.
Step 17: Read the FAQ and Forum Rules
Because they'll tell you how the community there likes people to act. They're there for a reason.