Keeping a weekly schedule diary between Au Pair and Host Family
From my own experience and some others Au Pairs and Host Family's stories it is a good idea to keep a weekly household diary. Letting each other know about there weekly routine helps prevent a lot of misunderstanding.
Au Pair is a big challenge, everything is new, country, language, culture. To make sure that the Au Pair will understand his/her duties write down the daily routine and then they can read it few time, check with the family if they understood. Describe in details at the beginning all the chores as it might be simple for you but for them as being in a new environment might be very difficult and very easy to make mistakes. For example if they have to cook or clean for you let them know how everything works around the house and what cleaning products to use. Or if your Au Pair has to drive book them few driving lessons to make sure they are confident to drive in your country.
Assuming that your Au Pair will understand everything just speaking to them or leaving them a short note on the fridge door when everything is new for them is a big mistake.
So, remember to be clear and make sure both of you know what to expect from each other.