For a good choice in restaurants you may want to try going to cheapeats.com.au.
Some of my favourites are Redgum at the Manly Wharf, Ziggy's at The Rocks, any one of the good Thai restaurants along King Street in Newtown or take a walk down Norton Street in Leichardt for some great italian food.
Thee are also some good restaurants in what they nicknamed Eat Street (church street) in Parramatta.
Phoebe