Many of the iTunes users I encounter don’t realise that they don’t have to tag tracks individually. iTunes is quite powerful when it comes to batch-tagging. Simply select the tracks that have some fields that should contain identical data (usually all the tracks from a single album), then select Get Info from the File menu, or (and you should learn the keyboard equivalents, for speed) Command-I (Mac) or Ctrl-I (Windows). This will open a window like the above. You will notice that you can change a number of fields for all the selected tracks. Where a field contains data, it means that all the selected tracks contain that exact textual info, such as the artist name above. If a field contains no data, it means that either all the selected tracks contain no data in that field or that some of the tracks contain different data. For example, you may have classified some tracks as Rock and others as Pop, on the same album.
The Multiple Item Information window is especially good for managing album art. As you can see, I’ve got an image in the Artwork field. I simply dragged a JPEG file into this field. When I click the OK button, all the selected tracks will have that image written to them. It becomes a permanent part of the audio file.
If you want to delete the information in a particular field for every selected track, simply delete the data (such as Album name) and a check will appear in the checkbox next to it to indicate that it will change. This also works with the Artwork field. To delete information in a field in which no data appears (e.g., genre, where there may be different genres), simply click the checkbox next to the blank field. This tells iTunes to make that field in all selected tracks match, which means it makes them blank.
If you use this powerful feature, you’ll manage your media a lot faster and more precisely.