Looks like the right forum
Go to options or Preferences > sharing > Shared folders . Here you will see what folder(s) you are sharing. Now you can either add the file(s) you want to share to the folder, or you can put the file in another folder and press add and browse for that folder and select it and that folder will be added to your shared folder(s).
You can also do this in the Limewire Library, but it is not quite so easy, and if you use the library, you might decide to stop sharing somethig and think you can press delete to remove it. DON"T this will delete the file totally and you will never see it again.
the files will be shared after you restart Limewire or press refresh in the Limewire Library.
I hope this helps