You just need to add this to your post
[yootube]XXXXXX[/yootube]
The XXXXX = the file number from the youtube video.
Here's the full link to my warp drive thing.
http://www.youtube.com/watch?v=GiAV7Z3Qcr0
The XXXX = GiAV7Z3Qcr0
So, the code would be =[yootube]GiAV7Z3Qcr0[/yootube]
I misspelled you tube so that it wouldn't embed the video. This way you can see what I'm doing.
At least that's how I do it.
I hope it helps ya out.