A list of every guide book I know of that includes overnight walks.
Information is minimal - some overnight walks are described in detail in the guides to Australia.
Kakadu and The Top End, (1st edition), by Mattias Breiter, published by Kangaroo Press, 1996, ISBN 0 86417 647 3. Primarily a tourist guide, there are only 4 pages on bushwalking but as it's the only advice, it's worth reading. There are no track notes, only advice on conditions and how to obtain a permit. Price is around A$20.