These came from the Official Sydney Guide. Not sure if they accept printouts. But to be on the safe side grab several copies of the booklet from a visitors center. (Some offers is one person max per coupon so you need multiple coupons for multiple people)
I picked up a copy from the Rocks Visitors center on lvl 1. But there it should be available around the Sydney CBD.
NOT ALL OF THESE OFFERS ARE GOOD. Its up to you to ozbargain out the better deals.
Some notable ones
Opera house $40 off opera tickets
Whale watching Sydney 15% off
Powerhouse museum 20% off
Taronga Zoo 15% off Adult and Child Admissions.
You can pick up a copy outside Town Hall on George St.