Limewire stores all of your files in a folder on your HDD called the Shared Folder, to find this folder click on one of your files in the LW library and select explore, your folder should show up...
So by uninstalling Limewire that shared folder won't be effected, but if you delete anything from there itunes will not be able to find it to play it....
To uninstall Limewire make sure you use the LW uninstaller which you will find in Start > All Programs > Limewire...
