"Unknown Artist" comes up on iPhone music library for some albums even though they have an artist in iTunes, Also some artwork not showing on iPhone even though the artwork for the album is on the iTunes library on my iMac

When you fix track names and album art in iTunes the information is written to an XML database and not to the file itself. You can use Doug's scripts to embed meta information to the file.

http://dougscripts.com/itunes/scripts/ss.php?sp=embedart

http://dougscripts.com/itunes/scripts/scriptcount.php

There is also an iTunes vbscript if you're using windows.

First, open iTunes on your computer. Then highlight all the songs with the same artist and select "Get Info". Make sure the artist name is under "Artist" AND "Album Artist". After you complete this with all the seperate artists, sync your iPhone.

That worked, thanks

I was also able to clear up this error by making sure "Part of a Compliation" was unmarked.