Hi Simone
I can't help with the subject of schools.
For accommodation, the Lonely Planet Guide might help.
Australia Travel Guide and Travel Information - Lonely Planet
Also, I would suggest joning British Expats and sending a PM to Professional Princess. Sam and Abdel moved to Perth about 6-8 weeks ago and are now renting a flat in Fremantle. I know they are on a tight budget for accommodation, so she probably has masses of info that might help you.
Best wishes
Gill