Instructions:

Enter your About Us Description in your administration area.

To embed YouTube Video, go to the video in YouTube.com.  Click on Share > Embed > Use Old Embed Code. 

Copy the code.  Then come to an article page such as this one in your Adminisrator Access. 

Click on the icon for html. ( It has <> on the icon )  Then paste the code into the popup.  Click on Update and then Apply or Save.  Preview your new embedded video.