If it makes you feel any better, I went to respond to the message that I sent to Santa because I was convinced that I sent it - I never hit send initially ...For anyone else who's a dummy like me:
"To sign up, you will need to do these 2 things (PLEASE DO BOTH):
1. PM @Santa Claus with your contact information (name, email, and country you're located in so that we can PM you the link to sign up on Elfster and join the gift exchange)."
(I didn't post #2.)