Once you're on the YouTube page for the video you'd like to place on your website, click the "Share" button located directly below it. Once you've clicked on that, another sub menu opens up in which you can click on "Embed". This will reveal the iframe script ready for you to copy and paste into Agility.
Copy the iframe script from here and within a Rich Text Area module in Agility, switch over to the "HTML" view and paste in your script. Done! You can now preview the video in the previewing environment and, once you're comfortable, you can go ahead and publish the video to the live site.
If you missed last week's Ask Akshay video on CSS Classes, you can watch it HERE.