Members that want to book a court but have not registered (or who are having problems registering / accessing the system), should send an email to email@example.com to receive help and possibly an updated registration invitation mail.
Non-members that have reached this page and are looking for a hit - great! You may need to first register with the Tennis Australia system if you haven't already - it's very easy (look for the little person icon to register/sign-in as necessary) - then go ahead and book a court! Typically courts 5, 6 & 8 will be available for non-members to book. [BTW, you'll need to use the same information and method of signing-in each time after your initial setup.]