okay, in simple terms: LimeWire and iTunes aren't related. you use LimeWire to download files of any type; you use iTunes to play music files. LimeWire's Library is not a "playlist", it's a basic file manager, and LimeWire is not a music-management application. iTunes uses playlists to manage music files. when you download files through LimeWire, they get saved in a Shared folder; after that, you can do whatever you want to with the files.

to make things even simpler for you, in order to play an mp3 file in iTunes, just drag it ANYWHERE in the iTunes window, then click on the play button. that's it. you can drag more than one file onto the window at the same time, if you wish, to create a bigger playlist.

you really should get familiar with your operating system and its applications, so you can better understand how things work, and what they do.

good luck!

zbell