yeah, i hardly used the warren, even though it's good, it has lots of 'descriptive' stuff about the various historians which you don't actually need to know. but it's helpful to give you an overview.
there are lots of books out, you will find the names of the people inside the Warren eg Arthur Marwick's 'THe Nature of History', EH Carr's What is History? etc. etc.
there are all historians considering what they think history is, and so you'll find they push their own views into their explanation, eg Marwick HATES postmodernists, and derides what they do etc. however, it's worth a look - you need to be quoting these people and if you have the book in your hands it's easier to remember the title and things.
BUT, the best book for the subject is called The Pursuit of History and it's written by a man callled John Tosh. It's completely amazing, i used it for my assessments, and the night before the hsc i read it through cover to cover and got 49 so i think it's exactly what you need to know. also what is good is a book John TOsh edited and it's collections of writings by people. but the best part of the book is his introduction, which can very easily be turned into a perfectly 'pasteable' what is history essay in the exam. --- you'd have to put in those board of studies sourcebook historians , some punchy quotes and then it'd be amazing good.
EDIT: not that you should do a 'paste' effort in the exam, you have to apply things to the question. but Tosh's essay gives a very good insight into 'how to write' an essay about historiography.
so yes, you should buy the pursuit of history (it costs $80, and you might have difficulty getting into it, but really it is amazing I can't recommend it enough) , and maybe just photocopy the introduction from his other book.
