I thought that I should share some of the tools that I use to plan trips with everyone and anyone who cares to read this blog:
http://www.whereis.com.au is a good website which helps you work out distances and is good at suggesting possible routes to travel. If you plot out a trip, it will automatically reate a cue-sheet with relevant distances listed in it. However, it gives no clues about hills, and often provides very little other useful information.
http://maps.google.com.au has a useful feature in street view which can be used to assess the condition of the roads that you are planning to take. It can also help point out the location of shops and service stations if you are lucky, as this information is often scarce or non-existant.
http://mymapshop.com.au is the website of "The Map Centre" in Parramatta, NSW. 1:25,000 topographic maps are usually about $9 each, and are invaluable for many country trips. There is no excuse for not having an adequate map! They have everything you would ever need in the way of maps, street directories, etc and the ladies who work there are extremely knowledgable. Just explain what you are after and they'll have it for you within minutes.
So there are my three main internet-accessable sources for trip-planning information. Many local government areas also have a tourist information website, and other travel websites contain snippets of useful information. Of course, other online tools such as http://www.google.com.au and http://en.wikipedia.org/ can help provide background information about towns, national parks and some camping areas.
Local tourist information centres or stands are also good for gaining local knowledge. I was lucky in that the centre in Picton was staffed by a cyclist who knew the local roads very well and was able to provide much useful commentary about the roads and hills and make recommendations of how to get to the various places on my trip. He even invited me to the local BUG's social ride!