How can I add album art to my iTunes library without going to the the iTunes Store?

I just got the the iPod Nano 4 generation and when I imported music into iTunes off of cds, the album art wasn't there, just the music note. I'd like to know how to add album art to the music I have so I don't have to go to the iTunes store.|||in itunes(not the store) under the advanced heading click get album artwork|||Google image search the album, and you'll get the album art. Select all the songs that are part of that album, and right click and select "get info" you'll then be able to drag the image of the album art into the little box that is for album art.