Sounds like a great trip!! I am from Melbourne and the last poster is true about Melbourne weather, we can get four season in one day. It depends on what part of November you are going to be here though. It should be warm but not too hot in early November, but get warmer late November. But as suggested before be prepared for anything!!!! As for the shore excursions, if you want to see some Australian wildlife, then definitely take the trip to Healseville Sanctuary, it's fantastic!! The Aquarium is also excellent. If you want to see some wonderful scenery, you can't beat the trip down the Great Ocean Road.
Have a wondeful trip!!!