Australia has state based historical BDM records available online. These archives will generally give you births up to 100 years ago, marriages up to 50-75 years ago and deaths up to 30 years ago. Read each site’s search tips to get the most out of them.
You won’t want to buy every record unless you’re really rolling in the $$$. Personally, I’ve only bought a few to find out specific details like cause of death or day and month of marriage. The index gives you a lot to go on for free but sometimes, especially if your ancestor has a common name or you’re struggling to find details elsewhere, you might need to buy the full record to check you’ve found the right person.
Before you cough up the cash, head to Graham Jaunay’s website to check out what you should find on your historical Australian BDM certificate (e.g. parents names, occupations, siblings, cause of death etc.).
Tasmania, ACT and NT are a bit different. I’ll do a post on them in a few weeks time.
Links:
Kindred Secrets 