Another FAQ:
Do you need to have done Accounting 1/2 to do well in Accounting 3/4?
In short, no. My school offers Accounting 3/4 in Year 11 without doing Accounting 1/2, which I took up. At my school, we had one Year 11 class doing Accounting 3/4 - no one in my class got lower than an A for the mid-year exam - which shows it can be done.
As may be the case with some students doing Accounting 3/4 in 2011, it's no disadvantage of not doing Accounting 1/2. True, it helps with the basic concepts of reports such as Balance Sheets, Cash Flow Statements and so on. But most of it, is re-taught again at the beginning of the year. You'll start on a "level footing", so to speak.
Accounting 1/2 helps if you have done it, though as you'll see throughout the year - the concepts in Unit 3/4 are vastly different from Units 1/2. If you are really that concerned, get a copy of a Accounting 1/2 textbook if you must and read over it. Though in short, I don't think it's necessary to have done Accounting 1/2 to do well in Accounting 3/4.