If you wish to post youtube videos in posts I have activated the option for when you make a new post...

Just click on the "youtube" icon when you are making your post and all you need do is to insert the YouTube Video ID of the YouTube video you want to add in between the tags.

The Video ID is the #ís and letters after the =

For Example: The Video ID in the YouTube Video link below is: xmLa_W_afH4

www.youtube.com/watch?v=xmLa_W_afH4

To post the video you would then put the Video ID in between the tags like this:
[youtube:2iruuvtb]xmLa_W_afH4[/youtube:2iruuvtb]