I've been adding cds to my itunes, but they're appearing with no album artwork but when i do right click > get album artwok it sometimes gets the wrong cover, for example if there is a single with the same name as the album then it usally get the singles cover.
If you scan in or get the cover from elsewhere, you can use the same controls in iTunes to replace the album art with your own (it otherwise gets the best it can find from the iTunes store, which isn't a perfect system).