It's pretty easy. The YouTube address ends with a bunch of letters and numbers. For instance,
this video address is
http://www.youtube.com/watch?v=BApMJPNCfPk. The bold text at the end is all you need to post a video.
Just like posting a link, use the code [/u2b] at the end and [u2b] at the front of the bold text. I added spaces in the below example:
[ u2b ] BApMJPNCfPk [ /u2b ]
When the spaces are removed, you get a posted video.
Feel free to watch this one. The player being discussed may be as good as Wilt Chamberlain was as a Kansas Jayhawk. If the rest of the team weren't scoring, he would have easily exceeded Chamberlain's 30 points in his first game.