To post a YouTube video use the following tags:
*YOUTUBE**/YOUTUBE*
(replacing * with [ and ] as appropriate).
Within those tags, you put the video id ... which is the bit after the "v=" in the URL.
For example, for
Code:
youtube.com/watch?v=Q6AKVMtj5Kc
the ID would be Q6AKVMtj5Kc and hence your tags would read
*YOUTUBE*Q6AKVMtj5Kc*/YOUTUBE*