EU nationals have an automatic right to work in France.
Most others will need a hard-to-get work permit, issued at the request of your employer, who will have to show that no one in France – or the entire European Economic Area – can do your job.
Exceptions may be made for artists, computer engineers and translation specialists.
Some travellers aged between 18 and 30 may be eligible for a 12-month, multiple-entry Working Holiday Visa, which allows combined tourism and employment in France.
Working 'in the black' (ie, without documents) is difficult and risky for non-EU nationals.
The only instance in which the government might turn a blind eye to workers without documents is during fruit harvests (mid-May to November) and the vendange (grape harvest; mid-September to mid- or late October). Though, of course, undocumented workers harvest at their own risk.
Au pair work is also very popular and can be done legally even by non-EU citizens. To apply, contact a placement agency at least three months in advance.