Congrats. I spent three years living in Port hedland back in 2002 and found it to be a great spot with family. It's got a really friendly 'small town' feel. Make sure you get involved in local activities (ie sports, etc..) to meet other families. The fishing is great even if you dont have a boat. It will take a while to get used to the temperatures though. It gets pretty hot there although you will get used to it. There's plenty of great camping places to see too. Millstream NP, Karajini NP, 80m beach. We spent 12 months living in South Hedland which isn't very pretty but not as bad as it's made out. We spent the last 2 years in Cooke Point which was beautiful. Beware the quality of housing there isn't what you might be used to in Melbourne and the cost of living is certainly higher than where you are now. Give yourself time to settle in, make contacts with other families and I think you'll fit in just fine.
rob