There are a number of places in Sydney where you can hire bikes and/or take a guided tour. There are also some people in regional NSW who offer specialised tours of their local area.

Bike hire

Bike Hire at Sydney Olympic Park

Centennial Park Cycles

The Watershed Cargo Bike Library at Newtown

Bike hire + tours

Bonza Bike Tours

Bike Buffs

City Cycle Tours

Electric Velo City

Manly Bike Tours

Sydney Electric Bikes

Regional tours

Australian Cycling Holidays  (self-guided, multi-day tours for regions south of Sydney)