I registered yesterday to be on staff at our National Jamboree in 2010. You can pick 5 different options. I chose Venturing, OA Service Corps, SR staff, SR HQ, and Trading Post. Figured I would try something different this go round.
If you go to http://www.scouting.org/ and look under My Scouting, you can sign up also. Be Prepared to have a credit card. They need a $100. deposit and $50. is non refundable.
If you are wanting to go as a Scout or Scoutmaster, I would wait and register with the BGC. That way you won't be out the $50.