Solar Victoria are the government agency dedicated to supporting the Victorian community install rooftop solar at their home and business, providing information, rebates and interest-free loans. The guides linked above are an excellent resource for comprehensive, independent information.
Finn Peacock (of SolarQuotes) has been a trusted source of advice on purchasing solar for over a decade, and this guide runs through many of the important considerations anyone going solar ought to be aware of. There are many useful articles on the website which address a variety of issues or considerations people confront when looking to install solar.
The Australian Energy Foundation have put together some of the more comprehensive guides to renewable energy technologies for the home. This guide goes through the ins-and-outs of going solar: what to consider and how to decide, how to go about it, and finally, how to make the most of your system.
These Canstar Blue guides provide a good overview of the basics of going solar. However, many aspects of deciding upon a solar system are be specific to your home, your energy use, and even local regulations. After reviewing the resources above, it is best to begin discussing your options with solar providers and comparing quotes.