WordPress.org

1. Upload the whole plugin folder to your /wp-content/plugins/ folder.
2. Go to the Plugins page and activate the plugin.
3. Use the Options page to change your options
4. When you want to display Youtube video in your post, copy the video URL to your post and change http:// to httpv:// (notice the 'v' character)

The video will be automatically embedded to your post in the proper way.

Example: httpv://www.youtube.com/watch?v=OWfksMD4PAg

If you want to post a high quality video (check if the video exists first!) you would use httpvh:// ('vh' for video high) If you want to post a HD (DVD quality, 720p) quality video you would use httpvhd:// ('vhd' for video high definition)

To embed a playlist use extension 'vp'

httpvp://www.youtube.com/viewplaylist?p=528026B4F7B34094

Additionally, you can set how do you want the video to be displayed in your RSS feed. Smart Youtube can show the preview image of the video (automatically grabbed from Youtube), the link to the video, or both. I recommend enabling only the preview image.