A friend of mine picked up a 'Biker's guide to getting around town' map thingo at a bike shop. Gives you all the nice backstreets.
I've also started riding with the Supreme Cycles group that do a run in the morning from Narrabeen to the City. I never knew how much you can avoid the main roads without adding to your kms. We spend about 2kms max on main roads, 20kms on backroads with no traffic, lights or problems.
It's definitely worth exploring the backroads, and if you can get a map, all the better.