Artur Malabarba has a nice post on embedding Youtube videos in Org files. I do that occasionally for blog posts by using the HTML embedding code that Youtube supplies with each video. It turns out, though, that you can do it directly from Emacs by defining a new Org link type.
This has the advantage that you can follow the link directly from the Org file or even export it to, say, PDF via LaTeX. It’s really easy to set up and once you do it would be easy to completely automate the link insertion the way I do for normal Web pages.
Malabarba has a separate post on how to add Org links that you might also find useful. If you frequently embed Youtube links in your blog posts and you blog from Emacs with Org mode, you should definitely take a look at Malabarba’s posts. They’re sure to pay dividends.