A few links that may be of use and/or interest:

Australian Model Railway Magazine

Australian Railways Historical Society (NSW Div)

Australian Journal of Railway Modelling

Australian Railway Detail Photos

Australian Model Rail-zine - Australian Rail Modelling on
                the Net

Phil Knife's Railway Pages - A wealth of information

NSW School Railway Clubs - The NSW School Railway Clubs' 

                 Association (The Railway News)

LocoPage - Information on many Australian Diesel Locomotives

Brisbane Model Train Exhibition