Can you elaborate on as to the areas of the Australian
east coast you plan to visit?
Purchasing a field guide dedicated to Australian
species would help you along your way.
Yep! If you plan to only visit QLD east coast, than "Field Guide to Reptiles of QLD" is really good, or if you plan on visiting QLD, NSW, ACT, VIC and TAS, "Field Guide to Australian Reptiles" this one has some pretty sweet little tables down the sides of the pages giving you a quick low-down on "the important stuff" about them, with a more in-depth description in the cente of the pages. Otherwise, an excellent one, that I have found anyways, is "The complete Guide to Reptiles of Australia, 2nd edition" These are all awesome books! But if you don't plan to live here or stay that long or return, than I'm not sure it would be the best investment...but then again, there's always someone who will take it off your hands afterwards on eBay!
Goodluck!