If you are looking for trained child care then au pairs are not usually suitable, although quite a few trained teachers do apply to us. (For trained live-in child care a nanny agency may be able to help.)
The au pair arrangement is classed as a "cultural exchange" rather than as the employment of a migrant worker in the normal sense. Au pairs don't need a national insurance number or to be registered for work with the DWP but there are special requirements that wouldn't apply to other posts.
Since the motivation of the au pair's stay is meant to be English language learning rather than making money, the language of communication within the family circle must be English. This is part of Home Office rules.
In effect, as hosts you will be important English teachers for the au pair. It is highly recommended that you make a little time to talk to the au pair each day.
If you are a non-native speaker candidates will invariably need to be reassured that your level of English is excellent and that you won't be communicating within the family in another language.
Au pairs expect two full days off per week and must be able to attend English lessons at least two or three times per week (if they can't realistically get there on public transport, a car will need to be made available).
We are now recruiting on the understanding that families will give at least two weeks pocket-money paid leave per year.
We believe occasional extra hours to be acceptable for EU au pairs but we don't arrange what is sometimes called "au pair plus" (due to the pay, tax, NI and worker registration issues arising).