What they do at Les Mills Auckland Central is hold a 'Starters' class one the first Sunday of every month. It's free, and while I haven't attended it, it is geared especially for newbies - more time and care is taken with regard to bike setup, riding position, responding to riding cues, etc. One week before the first Sunday of the month, posters go up saying, "Free intro classes this Sunday" - and Intro classes are also held for Body Jam, Body Combat, and Body Pump.
I primarily ride at Les Mills New Lynn which don't do any starter classes, and as a result, newbies are quite intimidated since the 'hardcore' instructors are the ones that attract the numbers, while the instructors who would be perfect for first time riders get ridiculous time slots like 6am(!?!?), which isn't accessible/desirable for those just getting started!
Good luck with the new timeslot, and hope it all goes well for you and your club 