a helmet can be hired for $5 on the day ($20 refundable deposit). They give you a hair net.
A license is needed, $20 for a day license, $50 for an annual which covers QR and Lakeside.
You're best to book in before the day as you get a $20 discount, though can do on the day bookings. Jump on the QR website and print out the sprint entry form.
I won't pre-book till thursday as I'll keep an eye on the weather. Don't want to be out there if it's much over 30deg. Tyres will go off in a couple of laps, plus it's just plain hot so will sweat my arse off.