I like Frommer's guides, having traveled a fair bit, and have read most of the available guide books for a particular area, I tend to keep coming back to Frommer's.
Australia is a big country, and Frommer's Australia is a fairly weighty tome ... and as such, I tend to read up and note down areas of interest and leave the guide behind when I actually travel ... this could always be put right if you could get an e book version ... you can't at the moment, but hopefully the advent of the new colour versions of Kindle et al will change that.
The book is beautifully laid out, and has a good balance between city and small town Australia and bush. The photos are terrific, and although I have been to Australia twice, and have driven about 5,000km ... I have only really scratched the surface.
Of the places I have been, Sydney, Brisbane, along the Queensland coast, Canberra and NSW, Melbourne and the Great Ocean Rd, and Perth/Margaret River ... the guide is spot on, I have stayed in some of the hotels and Guest Houses listed, and seen some of the sights, and find Frommer's to be pretty accurate. (that comes from using local authors I'm sure).
A guide book should be entertaining, inviting, colourful, accurate and honest. From what I have read so far ... that perfectly describes Frommer's Australia ... too weighty to take I find, but great for research.
PS ... Once you get there, the Tourist Offices in Australia are great.