Register all (potentially) attending adult leaders at meritbadge.info. You will need an email address, your council (use Mid-America not Mid America if that is your council), your district, your unit type and number, your BSA ID number and the date of your most recent Youth Protection training in addition to the usual information.
Any registered adult can register, update, or delete youth from their associated unit. In addition to class size, some badges have a minimum age.
Be sure that attending adults are registered in the Adult Volunteer class - we would hate to run out of food! The fee per adult is $10.. The system is incorrectly calculating it as $25 ($10 +$15), and we are working on getting it fixed, but you only owe $10 per adult.