<em>I'm going to receive six Australian clients tomorrow.</em> (Don't use "gonna" in everyday writing. It's slurred speech.)

Well, the usual things apply: be friendly, confident and polite. No need to "put on a show".  I can't really think of any taboo topics, unless there is something that you're doubtful of asking?

We Australians are easy to please. :)

I'll add just one thing: if you visit someone's house for dinner, it's customary for everyone to bring a plate of food or bottle of wine. It doesn't have to be much, you can just bring a plate of cut-up fruit. Everyone generally shares the extra food each guest brings, in addition to the main meal the host provides. It's not compulsory, but it's common and considered polite. No one will be offended if you don't bring anything.

We do the same thing for parties: each person brings something and shares it, so when you have a large group of people you have a selection of a wide range of cornchips, spirits, beer, soft drink, fast food, biscuits and sometimes there'll be one or two people who brought a bag of grapes.

If it's for business, I suggest just a plate of fruit and/or a bottle of wine. If you go to a restaurant, it will also be polite to bring a bottle of wine, just make sure you call up the restaurant first and see if they'll let you do that.

When it comes to paying for the bill, it will be polite to pay for everyone's meals, but don't be aggressive about it. Just offer to pay for everyone (or try to give the waiter the bill without the others even knowing to avoid a fuss) once or twice, but if they're really fine for paying for their own meals, let them. It will be polite to pay for everyone's meals, but it's not common or mandatory. We don't have a tradition of arguing over the bill like in China.

And most important of all, be friendly! Australians are much more informal in the workplace than Americans or Britons, so too much formality can be offputting. You can still be professional, but try to be friendly at the same time!

Good luck! :-D

Australians, in general, are easy to please. You don't need to feel embarrassed if you don't know something or can't say something in front of them.

If you have dinner with them and choose wine, ask them to pick which one they prefer. There is no problem.