Test if you meet the requirements (such as age, nationality, etc.) which entitle you to become an au pair in the Netherlands.
Find out what you need to take into account before leaving your country (what documents you need, etc.)(as an EU citizen, as a non-EU citizen).
What kind of support does the family expect from you? How many days off are you entitled to? Do you have to take part in a language course?
Do you have insurance coverage abroad? Will your driving license still be valid? Do you need a contract? What can you do for your safety?