Great questions. Absolutely a helmet is required for insurance reasons. However, if you don't own one the club has a limited supply to "lend" for the day. In order to guarantee one, contact Stuart Sherman at the trillium club, link to his email is on the registration page.
As an added bonus, the first 15 people that sign up for the school get a voucher for a free technical inspection. I think they usually cost somewhere between $50 and $100 depending on where you take it. But again, check with Stuart, he may still have some vouchers left.