The how to is on the lower left of the text box...
(When viewing the video on YouTube, click the "Share / (more share options)" link.
This will reveal a section titled Copy and paste this link into an email or instant message, with an edit box below.
Use your mouse to copy the link, return to your post and paste it in - the forums will automatically display as a video!)
But all I do is copy and past the
http://www web address, hope this makes sense.
Cheers Bob.
Edit, sorry yeh upload to YouTube first