A mate of mine forgot his Jepps when he went into the exam...thought he'd do alright anyway - and failed. So yeah, they are pretty useful.
ARFOR's and TAF's can be had in abundance from NAIPS. You should already have it installed on your computer being a CPL student but if not GET IT.
Then on the BOM site (or nightly news) just find the area that had the crappiest weather (ie not an area that is in the middle of australia which usually always have no subdivisions and benign weather. Then just go about diussecting each line and UNDERSTANDING IT. Ie try and put it into plain english what the forecast is saying.
If you can understand the more difficult ones (like 3 sub-divisions, many cloud layers, tempo's and inter's all over the place) then the exam won't worry you.