Thanks.
Here is the little trick to embed artwork in iTunes if you can't find the artwork elsewhere. Use the File>Library>Get Album function. As I said this does not embed the artwork. Previously iTunes artwork was of low quality but that is not the case in general now. Most covers will be of good quality 600x600 size.
Anyways once you have used the Get Artwork function now go to the Songs view with the Column Browser described above. Find the Artist then the Album you are working at. Highlight one song from the Album and select Get Info. You will now have an information window for that song. Go to the Artwork tab. You will see the album artwork in the window. Drag that artwork to your desktop. Close that window. Now follow the directions above for embedding artwork except first check the box next to the artwork window, select the artwork window and hit delete and OK. This breaks the link with the no-embedded artwork.
Follow the instructions again to embed artwork but now drag the artwork you saved to the desktop into the window and proceed. Now artwork obtained from iTunes is embedded.
This may be more than most wish to deal with but if you want high quality artwork to display on your monitor, iPad or HDTV this will give you the quality you need.