So I bet if Spencer is having trouble, a lot of you are as well! Therefore it's time for another little tutorial...
If you see a video on another blog that you like, click the icon at the bottom right corner so it takes you to the YouTube page (where you have the choice of size and background you might like to import to your blog). I prefer to do this rather than copy the code off another blog, as it seems to be clearer somehow.
Copy the YouTube Embed Code. Return to your blog post
Click on Edit Html in your post layout, as show in the picture. The tab is right next to the Compose tab. This brings up the post in html view.
Paste the code into the blog where you want it to be seen.
Publish Post when you are finished.
And here you are!