Lancelin - Lancelin lodge backpackers, also have motel style rooms (few) Trish and Trev are the owners and set it up for windsurfers!~ nice pool also!.
www.lancelinlodge.com.au/Geraldton - Sunset beach Caravan park is handy as you can sail straight out the front, but sessions cut shorter their as the wind swings Off Shore late, but also handy as is on the Coronation Beach side of town!
www.big4.com.au/Couple of backpacker places in town also.
Perth, have found a couple of places through stays.com
www.stayz.com.au/accommodation/wa/perth/hillarys(private houses with pools bit more $$up on the Nth Side around 'Hilarys), where you can then sail Pinaroo, Mettams pool, reef off Hilarys (if you want to play with white pointers) or drive to the river for flatwater 30-40 min off peak, also quicker Access to Lancelin if you just want to head up there for a day trip, not silly as often windier there than Perth by a lot (1-1,5hr drive), Hilarys is a residential area, if you want nightlife etc need to head back to City/Freo.
You need weed fin/s, and watch out for limestone reefs and Noahs, and think twice before sailing Scarborough beach on a big day, the shore break/rip is tricky as and eats gear, have no idea how those guys sail it!...Cottlesloe sth (used to be called Dutchies) or Leighton beach in that area are much easier to sail.
Enjoy the trip!