Invest in a really good book about horse health. It will probably be huge and look like a text book but it will be worth every cent it cost. Then read it, cover to cover even if your horse isn't sick or unwell. The good thing about these books is they will also give you all the warning signs to look for so you are able to catch any problem early so that things don't progress to a dangerous point healthwise for your horse.
Talk to a vet about vaccinations, generally in Australia you only vaccinate for tetanus and strangles as there IS no rabies in the country, or several other nasty diseases that they vaccinate for in other parts of the world - thanks to it being an island nation and having excellent quarantine standards!
Seriously though, pop in to Horseland or Angus & Robertson and get one or two books. If you can't afford them, go to your local public library and borrow them for free!!
All horses deserve, at least once in their lives, to be loved by a little girl.