How do Australian players usually look for decent casino sites? I am trying to find a resource with useful details.

From memory, that resource had a wide range of casinos licensed offshore. The listings seemed to cover licences, banking and withdrawals. The regulatory framework is tightly controlled, so plenty of operators are based abroad. The country of registration is only one factor.

I reckon it's this resource: https://australianonlinecasino.eu.com/en-au/ - make sure to review fees before signing up. If anything is unclear, contact the operator directly.