First, try this link
Airservices Document Description
This is my explanation. Someone will correct me and hopefully give you the right answer.
Civil Aviation Act - primarily deals with the delegation of powers to the appropriate authorities. Typically boring legislative crap that's pretty much irrelevant to day-to-day flight operations.
Civil Aviation Regulations - starts to get down to nuts and bolts. Deals with "big ticket" items like who's allowed to do what and when to whom in what sort of aeroplane. Rules of the air (giving way, minimum heights for flight over terrain etc.). Licencing requirements and priviliges and lims of licences.
Civil Aviation Orders - more nuts and bolts stuff. I guess kind of operational stuff but generally (but not always!) more theoretical in nature and stuff you might have to consider more of a preflight nature. Examples, rules for refuelling, instrumentation requirements, safety equipment requirements, flight and duty limitations, priviliges and limitations of ratings.
AIP - real nitty, gritty day to day operational stuff. Navigation requirements, radio requirements and phraseology, approach requirements (more IFR than VFR), forecast availability and decode.
ERSA - Specific Aerodrome Info - runways, taxiways, runway length, surface, elevation, fuel availability etc. All good gen!
MAPS - WAC's - large scale visual nav charts. No airspace information bit of a bugger!
ERC - Primarily IFR chart with airspace info on but no VFR stuff. Bugger!
TAC - same but smaller scale!
VTC - essential VFR chart for navigating in and around CTA around cpaital city and primary airports. Get 'em and make sure they're up to date!
VNC - 1/2 way between a WAC and a VTC with the added advantage of airspace information but 1:500,000 scale makes them pretty big.
PCA - planning for met boundaries and points, VHF coverage etc. Sometimes not much use but other times bloody handy!
Hope this helps. Good luck!
PS You owe me a beer too!