Metadata tags describe your movie's content in a fashion similar to id3 tags for mp3 music. The metadata is then used by iTunes, iPod, iPhone and Apple TV.
Adding Metadata to your Movie
Adding metadata is easy. Just navigate to the Metadata pane using the main toolbar.

Then click "Add metadata to the exported movie"

Now all metadata related controls will be enabled and it's time to start adding some data.
Video kind
First you will be presented with a popup where you can select which kind of video you are working with. You have 3 options, each will affect where the movie ends up in iTunes or on your portable device. There's Movie, TV Show and Music Video.

If you select Movie your file will be found under the Movies section in your iTunes Library. TV Show will sort under TV Shows and Music Video ends up in Music.



Movies
Movies will have the following metadata tags.

Producer and Director will only be visible in QuickTime Player at this time.
TV Shows
TV Show has the following tags

It will look like this in iTunes

And like this on an iPhone/iPod Touch

Music Videos
Music videos has the following tags

It will look like this in iTunes

Tips and Tricks
You can copy the metadata from one movie to all the other movies by using the copy button.

About Metadata
A movie with metadata may not be playable on all devices. It's known to work in iTunes, iPod, iPhone and on your Apple TV.