Registering a Domain
When you register your domain you are actually purchasing a license to use that name for the amount of time that you purchase it for. If you fail to renew the domain once the license period has ended, it will go back into the pool of available names and someone else may purchase it.
To check if a domain name is available try the MelbourneIT domain search.
Once you have selected your domain name, you can get your web developer to register your domain for you or alternatively you can register your domain yourself online remembering that your web developer will require the registry information to point your domain name to the hosting location for the site. Be aware that pricing can differ quite dramatically between providers and that the cheapest option may not always be the best.
It is VERY IMPORTANT that your domain name is registered in YOUR NAME, not that of your web developer, AND that YOU receive the registry key details and store them in a safe place. After all, YOU own the domain which is a business asset, like any other.