You also can log onto www.wotif.com to have a look, and you can book online if you like, or you can google say "Perth accommodation" to get some other websites.
Just a reminder, it is quite hard to take a rental house in Perth at this moment if you prefer to renting alone. So you may have to check newspapers to seek any shared accommodation after your getting there. Any way, good luck.
By the way, I am in WA, but not in Perth.