Hi meloca,
You won't get arrested for burning MP3's to CDs, or ripping CDs to MP3s either, for that matter. LimeWire doesn't do CDs, so you'll need other softwares to do that. Most Windows users can find their MP3s that they downloaded with LimeWire at "C:\Program Files\LimeWire\Shared" unless they specified LimeWire to save files elsewhere.

Most media players nowadays can burn MP3s to a CD-R on PCs with a CD-R drive. Players that can burn CD's include: WinAmp, iTunes, and Windows Media Player. You can get them from:

http://www.winamp.com/
http://www.apple.com/itunes/

(Windows Media Player is usually already installed on your PC because it's made by a monopoly.)

For converting CDs into MP3, I recommend CDex: http://cdexos.sf.net/
iTunes is also pretty good at converting CDs to MP3, but you need to configure its preferences first before you can do that.