You might choose to take complete care of your Jammers, providing materials, tools, mentors, food, drinks, even accommodation—wonderful. Or you might say “Bring everything you need…” and give them the phone number of the local pizza guy.
It’s up to you—just make sure your Jammers know what to expect.
However you decide, unexpected things will happen. So make sure that someone from the Organising Team is always available to help Jammers and to fix problems—and this person has the resources and contacts to do the job.