<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/UHwSk8bFS4M"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/UHwSk8bFS4M" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>
Take the URL of the video, and dimensions, then put in this format:
[you*****tube width=425 height=350]http://www.youtube.com/v/UHwSk8bFS4M[/you*****tube] remove the ***** - just for example's sake.
Youtube:
Matriarch