The most puzzling aspect to most of our clients is the 'modular' aspect of preparing a new web site.
There three separate things to consider -
Firstly, you have to register your domain name. That's your web address. Mostly commercial enterprises in Australia have the suffix .com.au. That's the one people will guess if they don't know, so it makes sense to stay with it. Have a look at Securing Your Name for more discussion.
For hosting you'll need to rent some space on a web server so your actual web site can live there. More discussion on Web Hosting.
Next step is web site design. You discuss your requirements with a web designer. If you already have a corporate identity your web site should follow the design to strengthen your branding. If you're a new business you will have to decide things like corporate colours, logos. Your web designer may be able to help you with that - we can at Great Webs. See the Web Design page for more info.