Our favourite is the “Banksia Tourist Park” in Hazelmere, which is also not too far from both the Domestic and the International airports. A VERY quite location with good clean shower and toilet blocks.
For further information: http://www.banksiatourist.com.au/contents/contact.html
The “Midland Gate” shopping centre is only a few k´s away which is a modern shopping complex and a good place to get all your food and travel needs before you start your trip.
If you do decide to stay it would be advisable to book in advance as it can get full, mainly with interstate visitors which is always a good recommendation.
Regarding an accommodation guide, when you get to Perth go to the local RAC WA (motoring club) office and get a copy of the “RAC WA Accommodation Guide 2013” it will have all the information you need for your trip. I don’t know if they will post it overseas to you but you could e-mail them and ask. http://rac.com.au/Travel/Holiday-guides.aspx
Scroll down the page till you come to the RAC WA Accommodation Guide 2013 it’s A$8.50 for non-members but if you belong to a European affiliated motoring club and show your membership card you might get it for free
Kind regards, Aussie1