hey mate,
there is a camping and wheeling trip this weekend just north of perth.
http://www.auszookers.com/index.php?nam ... ic&t=14251
come along even just for a day, best way to learn is to get out there and do it. your car should be fine even if its stock, i took mine there stock and it was sweet.
to answer your question though.
ya gotta let ya tyres down to about 10 psi, if its really soft sand i use low range and then just drive as normal, ie so the revs arent screaming but its not gonna stall either.
i found my old all terrain maxxis 751's much better then my new mud tyres on sand.