Hi Listener,
the bad news is that all snakes in Australia, except for some breeds of python found in the north, are venomous enough to kill humans. In WA there are some little worm-like ones (I can't recall their name) that are less than a foot, and even they can potentially kill.
I think statistically, the biggest killer is a type known as the Common Brown Snake. It is a drab snake, and the reason it is the biggest killer is it is, well, so common. Next on the list is the Tiger Snake. It is dangerous as it is (as far as I know) the only snake that might actually attack and chase you.
The good news is that deaths from snake bites in Australia are rare. Far, far more people are killed in other parts of the world by supposedly less venomous snakes, such as Russell's Viper in South Asia. There are a variety of reasons so few deaths occur. Snakes rarely venture into urban areas, people know how to avoid them, good anti-venom is widely available, and most snakes won't attack unless trapped or cornered. Also, despite their venom being extremely poisonous, Australian snakes usually don't inject much into a victim. My brother got bitten by (most likely) a tiger snake and survived.
Here is a true story; my dad was walking along a track through native bush, and suddenly found a tiger snake in his path right in front of him. He kept still and his eyes directly on the snake, and slowly crouched down, to pick up a stick that he could see in his peripheral vision. But as he put out his hand for the stick, the stick slid off into the bush.
For the benefit of anyone thinking of coming to Australia, I should add that it is not in any way as dangerous as it may sound. In fact, it has all been overblown. If staying in the major cities, you are safe from pretty much any of the venomous or poisonous animals, and even in remote country, you are safe provided you take a few basic precautions; eg don't swim in a waterhole where there are crocodiles, don't walk through long grass unless wearing closed shoes and long pants, etc.