For Mac, only the OSX version of Limewire has a built in player. You should download itunes (although there are other mp3 players). Here are the links for each version of Mac OS:

OSX

OS9

OS8.6

Once you've got itunes up and running, do the following:

1. Go to shared in the library window in Limewire and note the location of your shared files.

2. Go to this folder in the finder, select it, type commamnd M and drag the alias onto the desktop.

3. When you want to put your downloaded mp3s into itunes, open itunes and the shared folder beside each other and drag the mp3s into the itunes window. If they refuse to appear in itunes, drag them onto iTunes Associator first.