As with yourself, there are two aspects of this ie what to do before you come here and what to do after you get here.
Before you get here, you should try to encourage your kids to enrol in French classes where they are available. If you're near a large town or city you may be able to enrol younger children in French language playgroups and the like. One thing that you shouldn't do is to speak French to the children yourself as this way they'll pick up your French accent: we've heard many British children who've been here for some years still saying BON JURE rather than BO ZHUR simply because their parents spoke French to them from the start. Take particular care that playgroup leaders are native French speakers.
When they get here, if you can, you should enrol 2 to 11 year olds in a French school (more on education later) and 12 to 18 year olds in a bilingual school. I recommend bilingual so that your children can keep up their fluency in English as well as French; we've touched on this aspect several times in the past which are worth reading to see the kind of difficulties you can find with French language schools for older children.
Next we talk about the local languages in France and what to do about them.
