For you Jeni:
Find a YouTube video you want to share. Directly to the right of the video box there's some blue lettering marked "embed". Click on that so it's higlighted, right click the mouse and copy the code. Go to your blog page and start a new post. At the top of your blog post dialog box you will already be in the "compose" tag. Click the "edit HTML" tag. Click in the dialog box and paste your code into it. Click on the "compose" tab and you'll see the video in your new post. You can click in that dialog box and hit enter a few times to give yourself some room above the video so you can type what you want. Let me know if that works for you.
Here's my absolute favorite video for you.