Browse to youtube.com
Find the video you want to embed in your site, and display it.
Click “share”, then “embed”. There will be a text box with code selected. Copy this code. It will look something like this:
<iframe width="560" height="315" src="//www.youtube.com/embed/XervzRyXukY" frameborder="0" allowfullscreen....
Now go over to Sitemaker to insert the video.
Click on the “insert” (+) icon, and choose the
HTML snippet object.
Click on the “Setup” tab, and insert the code you copied in the resulting box.
Save the changes.
Resize the window if prompted.