what topics are you doing, hatty?
for resources university libraries are often your best bet because they're a 'one stop shop'. you can get a card at fisher library [on the univeristy of sydney campus] which costs about $50 for 6 months. i did that and found it VERY useful.
if you have money to spend, abbey's bookshop which is just opposite the QBB is REALLY good for history, and gleebooks on glebe pt rd is nice too.
when you look for books, check your text book bibloigraphy first - that will usually identify all the major historians. and obviously, being familiar with these historians will help you write better essays - the markers feel nice when they know the historian you're talking about, and these 'big name' historians slag each other off lots, and if you can understand the concepts they debate and write about them, then you'll be set.
