English Language yr 12 is great, although you'll have a different study design for 2012, however they won't give you 99% of things that weren't relevant from last year, because past vcaa exams for englang need to be relevant for some topics. Collection of Articles aid to provide evidence for your essays, perhaps providing 2/3 points for analysis in your essays. For example, swearing relates to the topic of dysphemisms, often you'll find high profile people swearing on perhaps 'delicate' matters and in your essay you sort of describe the consequence of their actions etc.
Sac-wise, this is how my school did it:
1st sac- scrapbook sac. We were given complulsory articles and had to find our own articles to which we were given questions on both e.g. action of euphemisms/ dysphemisms etc.
2nd sac- Some kind of spoken analysis, part attained to the Unit 3 structure, e.g. about slang, euphemisms, dysphemisms
3rd sac- Spoken analysis unit 4, about maxims of cooperation, conversational strategies e.g. tag qs, holding/ handing over the floor, maintaining a topic/ topic changes. We describe the 'actions' of these conversational strategies, analysing a piece of spoken text, e.g. was it cooperative- can talk about the maxims, or handing over the floor etc. This was a spoken language analysis in the form of an essay.
4th sac- Written sac analysis, things like onomatopeia, punctuation, things like semantic stylistic features/ syntactic stylistic features etc. Was a q/a sac.
Generally you follow transcripts/ passages they'll provide a key of various prosodic features, which you often have to analyse e.g. pace of speech, emphasis on certain words- the influences of these.
Essays are for persuasive purposes normally, and q/a things are like a discussion.