Not sure what you're allowed to pack in your airline baggage? TravelSECURE offers the official word straight from the government's mouth.
While you'd think that finding out relevant travel security rules would be a matter of a simple search, there's a fair amount of pollution (overseas information, desperate travel site traffic seekers) on Google and other sites. TravelSECURE offers a useful summary of the relevant rules for both domestic and international flights (the latter are the ones that ban liquids and gels). The other key government site to check before heading overseas is Smartraveller, which contains specific country advisories on safety issues.