Nest boxes are a great way to add habitat to your site and are a good hands-on project to undertake with kids.
Here is a list of some websites that will help you get the ideas flowing and show you what you can do to encourage more birds to your environment.
The Lifestyle Channel
Paul West from River Cottage Australia gives a step-by-step demonstration on how to build and install a nest box.
Birds in Backyards
Looking to build a nest box to attract a specific bird species? Birds in Backyards and BirdLife Australia have created nest box plans for a number of native Australian bird species including the laughing kookaburra, green rosella and Australian owlet-nightjar.