it's almost like adding the pictures, there is a twist
you can either type out the "[ yt]""[/ yt]" tags or when you hit go advanced or if it is a new thread hit the little "youtube" logo button up by the same bar where the image tag button is....
you have to copy the part of the URL in the youtube video after the "="...
www.youtube.com/watchxyz=*insert random letters*
the bolded part is what copy and paste between the [ yt][ /yt] tags...
make sense?