The quickest and easiest way is to directly embed the Youtube HTML into the body of your post itself.
Ensuring the media on your site is properly optimized means it will load fast and still provide a good user experience.
If you are trying to search engine-optimize your website, you need to understand the following terms in the SEO Terminology
The Global Redirect module can painlessly eliminate duplicate content on your Drupal website
In this witty discussion from the 2006 Gel Conference Seth Godin shows things that are poorly designed
Thanks to Drupal, it is very easy to set meta tags for each node with the Meta tags module.
Decoupled Drupal Has SEO Implications. Read more on what that can mean for your Drupal site.