You should start noticing that there's a little button when you post a thread in the editor that says "tube" when you click that a you tube code will appear in your post that will allow you to embed a video from Youtube right into your post instead of having to link to the video. Pretty cool and it works!
The tricky part is that all you need to put inside the youtube tags is the weird filename of the video. For example: http://www.youtube.com/watch?v=o1vovoKycNI you would just put the very last part "o1vovoKycNI" within the tags. See Below: