The sales notes that go out with a new album are called a "one sheet" for a reason - they are one page. Keep your introduction to the label the same way. Avoid starry eyed prose detailing the way in which music moves your soul. Instead, tell who is making the music, where you're from, any success you've had playing in your area, and any upcoming shows you have planned. Include your email address. You can include your phone number as well if you want, but never put your phone number exclusively. You're very unlikely to get any feedback that way. Keep the demo brief as well. Three songs or so will do it. If they want to hear more, they will let you know.
Source : lovetoknow.com