In short, I don't think Business is a particularly difficult subject, but there is a fair bit of content to remember. Thus, I think it's important to be consistent during the year (rather than leaving doing all of your notes etc. until just before the exam).
To do this, I used my spare time to consolidate my notes, having two books: my usual notebook, which I used in class, and a revision book. I added to the revision book gradually, essentially working through the study design's dot points as we learned them, and by the end of the year, I had a great revision resource. This meant that I could focus on practice exams, which I found greatly beneficial.
In terms of SAC preparation, everybody is different. Personally, I tried to relate the information to what I knew (mainly sports!). The more practice questions you can do, the better (and then get them marked!).
All the best.