More on the 12 string guitar...
Trumpy is right about the octaves, except for the high strings B and E, which are the same octave.
http://www.guitartips.addr.com/tip28.html It's not too difficult to play it, since you play two strings at a time, versus one string on a regular guitar. It sounds sweet, like you have a chorus of notes. The best sounding 12 strings are acoustics and the jingle-jangle Rickenbackers.
