Having just done VCE, I'm glad I didn't do that much over the summer. Year 12 is an incredibly draining year, and you don't want to work hard over the summer to find that you're burnt out around exam time.
Personally I just read my english texts, did most of my set homework (though not all

), chilled and actually enjoyed my summer. If you have trouble with some areas then maybe look over them - but otherwise I'd just make sure you are organised for the year ahead. Might just be me, but I don't think there is much benefit learning the course over the summer - it will just drain you before the year starts.
Also,
have you forgotten what awaits after VCE
Seriously, just keep this in mind during the year. You have no idea how amazing life is after exams are over!