Tasmania, Info Please

We are heading for Tassie next Aug for 8 days, starting at Launceston and
finishing at Launceston. We plan to to hire a car and drive ourselves, most
likely staying at motels. We are a couple of "mature age" people and we are
wondering if anyone who knows Tassie could give us some ideas of what places
would be good to see. We aren't into hiking, but we like history and nice
gardens plus anything interesting. For instance I hear that the Cadbury
Chocolate factory is well worth a visit, any suggestions would be
appreciated.
Does anyone have experience of the driving time from Hobart to Launceston?
Thank you for taking the time to respond.
Carl