Hmmm, well I'd say that you probably don't need to put six songs on a demo, thats most likely a waste of time...standard demo tapes are 3 songs, put your best one first. Send it with your press kit (photo, bio, reviews) and don't send it unsolicited (talk to someone at the label, tell them you have a demo that you'd like to show to them) otherwise it'll probably get tossed (another good reason to not do six songs). try to put it on CD if you can, more and more bands are doing this. It doesnt have to be professional studio quality, but now that everyone and their momma has a digital 8-track, it would be a good idea to make a nice recording. You probably don't have to do gigs first, but if you have reviews (see above) it helps. Good luck and keep trying.