You might want to read over the forums for the SoTTT exchange and the Batiks-R-Us exchange and Sensational Strippers to see how Deb and Ritzy and Barb set up their guidelines, and fielded questions.
You will need to post your guidelines on the forum.
You will need to promptly answer any questions that arise on the forum, or through e-mails.
You will need to be the receiver and sorter for all the participants. It helps if you can get other people to help you sort.
You will need to return all packages after they have been sorted, and fill out customs forms for any international participants.
You will also need to arrange for postage for the the international participants. So far personal PayPal accounts have been used.
Depending on how many participants sign up, this could be no big deal, or it could be almost overwhelming!!
I don't mean to scare anyone off, but those are things that we have learned and dealt with since the first exchange was proposed!