First, you need to read the General Games Section rules, which all apply here. Here are the rules specific to the Team Fortress 2 section:

This is NOT the place to advertise your server/youtube channel/etc
This is NOT the place for Steam/game related issues. - For game problems or support, USE THE MEGATHREADS or Chat Thread. or ask Steam Support & Google. If you think it's happening because your computer is broken, use Hardware and Software forum.
Don't make threads for your dumb ideas other than in the megathread, you will be banned if you make a new megathread when one is already active. Look for it.
Use Google and/or appropriate megathread for your questions - Don't make threads. You will get a full 3 day ban for these.
Did Valve do something you don't like? We don't need to hear about it; don't make threads about it. - USE STEAM FORUMS OR YELL IN MEGATHREADS.
Don't make dumb threads about how you got scammed/hacked. We don't need to know that you are an idiot.
Don't make "post your" threads.
Post TF2 videos in Videos And Flash Movies and That Kind Of Crap Or In the appropriate megathreads. If you made a video of your own (with Source Film Maker, 3D modeling, etc) you may have a thread of your own, provided you put some actual effort into the thread and make discussion. Don't just post the video.
Don't make scam threads or shop threads (e.g. avatar for item shop)
If your game broke because of an update, you can find out why/how to fix it in the current update thread. Don't make a thread about it.
As a general rule, questions should always be asked in chat threads/megathreads first. If there is no relevant megathread, search the section for threads with similar questions. If you're out of options, please make a well written thread about your question or problem.
About Update threads: ONE UPDATE THREAD for the entire day. Duplicates or multiples will just get merged.
Title should always have the date, then (optional) if it has a title, followed by declaring if it is a patch or update. The body should consist of: Official links, the change log in quote/release tags, and your input. Read the first page before you post. A confirmed update leak can have it's own thread.

About giving away Free Items and Raffles/Mega raffles: Scams get you permaban, Raffles MUST have a end date, Follow the entry rules.
There can ONLY be one Free Item thread, no shitposting.

Report threads and posters that you see breaking these rules. We'll be there, this place should mainly run itself.

PM a moderator if you have a rule you'd like added to the list.