If you would simply like to link to the video, you can either post it as a URL, or post the URL itself. Posting the URL by itself will automatically detect the name.
Code:
http://www.youtube.com/watch?v=9PGe_ZAxTWs
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If you would like people to be able to view the video on this website, you need to take the youtube video code from then end of the url.
Code:
http://www.youtube.com/watch?v=9PGe_ZAxTWs
Video Code:
PHP Code:
[youtube]9PGe_ZAxTWs[/youtube]
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How to post a YouTube video 
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