I've noticed a lot of incorrectly posted YouTube videos, so here goes:

When you want to post a YT video here on the forums, you use (YT)(/YT) tags, replacing the parenthesis "()" with brackets "[]".

Here's where many people mess up.

Let's take the Numa Numa fat guy dancing video -- purely because I find it funny and it serves as an example.

This is the link: http://www.youtube.com/watch?v=60og9gwKh1o

The incorrect way, which will likely result in a video that does not work correctly, would be to put the entire link within the YouTube tags. We'd get this:

(YT)http://www.youtube.com/watch?v=60og9gwKh1o(/YT) <--------What it looks like
[YT]http://www.youtube.com/watch?v=60og9gwKh1o[/YT] <--------Not working video

So how do you post a working YouTube video? Simple!
You see that part of the link that says "v=?????????????"?
Simply erase everything but the numbers after "v=".

We get this:

(YT)60og9gwKh1o(/YT) <--------What it looks like
[YT]60og9gwKh1o[/YT] <--------Working video

-----------------------------------------------------------

Another thing people might not know: you can edit the video's tag so that it auto-starts at a set time.

All you do is add #t=s to the end of the video tag, where s is a number of seconds.

For instance, this is the video when you start 60 seconds in:

(YT)60og9gwKh1o#t=60(/YT) <-------What it looks like
[YT]60og9gwKh1o#t=60[/YT] <-------Video starting at 60 seconds

Thanks to ByOdinsBeard for pointing that out.

I hope this clears up any confusion up!
Feel free to leave questions.