John, go to the the top of your screen and copy the URL on You Tube, then in the full reply screen click on "enter media tag", select you tube, then paste the URL in the space that pops up. It is very similar to posting a picture.

example
URL
http://www.youtube.com/watch?v=mUNBwqovI9U

I added a * in front and behind the URL so you can see what the link looks like before your post.

[video:youtube]*http://www.youtube.com/watch?v=mUNBwqovI9U*[/video]

without the added *


laugh