Embedding YouTube and other videos in WordPress blog entries is kind of annoying. You can’t just flip over to the HTML viewer and put in the embed code. A lot of the ways I’ve seen online have been to turn off the rich editor, which is really annoying.
The best way (ie fastest and easiest) way I’ve found is to get the TinyMCE Advanced plugin. Then, go into Manage>TinyMCE Advanced in your wordpress admin area and drag the little button that says a little blue “HTML” onto your toolbar. This button, when clicked, brings up the HTML source of your blog entry.
Now, when you go to write a blog entry, the little button with HTML should show up. Click on it and the HTML source will open up. Paste the embed code from the YouTube page or wherever.
Viola! Easy as pie!