I don’t know if it is just me, but a lot of the stuff I have downloaded from the Mises iTunesU page has missing artwork or artwork that doesn’t look like the ones on the download page. Here is how to fix it:
http://picasaweb.google.com/MisesInstitute/ITunesUBadges#
Download the artwork for the set you are looking to fix. Right-click on the name of the audio book or other media that you want to add artwork to, and click the “Get Info” option. Then simply drag and drop the artwork you want into the little box labeled “artwork.” You’re done!
Hope this helps anybody who has been frustrated by iTunes!