What you see above this sentence is the post featured image. It appears automagically!
And if you use an RSS to email service like Feedburner or MailChimp, your featured image is part of your RSS feed, too!
What about videos?
Want to highlight a YouTube video or some other sort of video in a post? It’s easy! Just follow the WordPress guidelines for using an embed. For example, below is an episode of the Genesis Office Hours podcast featuring Brian Gardner.
(hint – I just pasted the YouTube link in via the post editor “Text” mode and the video magically appeared)