Not sure what you mean by the library icon. If you mean the tab at the top of the viewing screen in Limewire click View >Show> Library.
Your tunes must be transferred to iTunes from your download (or save) folder, not from the Library (see Limewire ..Tools>options>saving>save folder for the location of the folder.
This link should help.
http://gnutellaforums.com/open-discussion-topics/36230-how-transfer-music-my-ipod-itunes.html
BTW DO NOT USE DELETE FUNCTION TO REMOVE ITEMS FROM LW LIBRARY ... use rempove from share!!!!!
Let us know if you need more help or if I have had a mental block and missunderstood the question