A list of every guide book I know of that includes overnight walks. Some are out of print and only available in libraries or as second hand books.
There are very few guide books published to Western Australia. This has probably resulted from the lower population and isolation from the remainder of Australia. I have seen one proposal for a book of overnight walks. As the author has never written a book before and did not seem to realise how much time it requires, this might not eventuate. Most books to Australia ignore this state as well with the exception being Bushwalking In Australia. The new 4th describes 4 walks in Western Australia.
A Guide to the Bibbulmun Track, northern and southern half (3rd edition, sort of - the track is almost all new), published by Department of Conservation & Land Management, 1998, ISBN 0 7309 6874 X and 0 73096876 6. The official guide to the Bibbulmun Track is now divided into two books, the northern and southern half. Overall the notes are fairly accurate with only a few small errors and the books are well worth having if walking the track. The books are designed to be used while on the track and are short of some information needed to plan a walk (see my web page for some extra planning advice and you should also contact the friends group). Price for the guides is around A$30 each.
Mountain Walks in the Stirling Range, parts 1 & 2 (1st edition), by AT Morphet, published by Torridon Publications, 1996, ISBN 0 646 29137 8 (or part 1 - 0 646 29138 6 and part 2 - 0 646 29139 4). Describes all walks and walking routes in the Stirling Range using line diagrams. For those wishing to do the overnight traverse of the range from Bluff Knoll to Ellen Peak, then only Part 2 is needed. Price for each part is around A$15.
The Cape to Cape Track Guidebook, by Jane Scott & Ray Forma, published by Cape to Cape Publishing, 4th edition, 2008, ISBN 978 0 9803337 1 8. An 112 page guide with colour topographic maps and many photos for the walking track from Cape Naturaliste to Cape Leeuwin in the south-western corner of Western Australia. Price is A$22.
Bungle Bungle Range, by Dean Hoatson & others, published by Commonwealth of Australia, 1997, ISBN 0 642 25010 3. This is an 82 page booklet that is mainly a guide to landforms, plants, animals etc. For overnight walkers, it does give a brief description of the only overnight walk allowed in the park to Piccaninny Gorge. The notes just give points of interest and have no campsite or camping rules. Price is around A$20.