Google is your friend. It could have easily gotten everyone of theses answers. Please search next time.
You can use something like gimmesometune to auto download lyrics, and needledrop script to play each of your tracks for 20-25 secs and let it run on mute all night, so it will play/fetch lyrics/artwork for all the songs.
VisualHub is good for converting or the free version called iSquint.
Also If you need to add artwork by hand, I would look on amazon or google image search to find the image, and then right click on song/songs in iTunes, and click get info and then drag and drop it into the box on the artwork tab.