same as thread
That's all done through the Info window of the song. On a Mac, select the song (tv show, movie, etc) you want to change info for and press the Command and I keys, or from the File menu, pull down to Get Info. You can select more than one song (movie, etc) at a time and change certain settings for all of them at the same time. The thing you can't change on multiple items all at once is the type of video it is. So you have to select each one individually and then Get Info and under the Video tab set the Video Kind to whatever you want it to be. Then you can select all the files you want to change at the same time and give them the same info using the Info tab. The way I figured out how this works was part trial and error and part seeing what iTunes does. I selected a TV show I had downloaded and checked the settings that iTunes had given it, then just followed that outline for my home-made shows.
Hope that helps