Alan
Put simply and generally, guitar cables are not balanced but mic cables are. Both types are screened to minimise noise and interference pick up ie they have the signal carrying conductors (insulated) within an overall cover often of braided copper which is connected to ground.
A guitar or instrument cable has a single inner conductor and screen.
A balanced cable has 2 cores and each core carries a version of the same signal that is out of phase with the other so that any noise occuring in the cable run is cancelled out within the cable. Balanced cables terminate in 3 conductor connectors, often an XLR (but that in itself doesn't guarantee the cable is balanced) or a TRS (tip/ring/sheath or "stereo") jack.
Speaker cables may have as few as 2 conductors (more for bi-amped etc set ups) and are not usually screened. They may terminate in jacks or Speakons or terminals suited to binding posts etc (more usually Speakon or jacks in a PA application).
A stereo cable (which is what you may need to hook up the cd players etc) has 2 conductors within a screen but to distinguish this from the balanced set up, each centre conductor carries a different signal (right and left channel).
A decent explanation here:
http://www.soundonsound.com/sos/jan02/a ... aq0102.aspJim's link to Studiospares will take you to a host of different options
Roger
