When posting videos & images in the forums, you have to use BBCode. Here is a quick tutorial on posting youtube videos here in these forums.

Step 1
Go to the youtube page which has the video you want to post.

Step 2
Locate the URL in the address bar and copy the video code (v=******). In this case, the code we want to copy is 'XoRmjS7Wc-o'. See image below.


Step 3
Place the video code in between youtube open/close tags like this...


That's ALL!!!