How can I find out the best streets in Yanchep?

Check out places like Real Estate.com.au and read the suburb profiles and check what the write up about properety on sale says. See which house seem cheaper or more expensive and use it as a starting guide - and of course, see how far away the water is! Get out google maps on the internet and use street view to drive around and see fro yourself what the features are and then go for a real drive to confirm.