I've moved your post into a thread of its own in hopes of stimulating a bit more discussion.
First question is, of course, what sort of visa are you planning on getting for the move? If you are hoping for a work visa (i.e. employer sponsored), it will be very tough going. Basically, there are more than enough native English speakers willing to teach English who don't need a work visa, so you'll be at the end of a long queue.
If you have another sort of visa that gives you working rights (spouse visa, student visa, etc.) then your best bet (at least at first) might be to post notices in the local bakeries, butcher shops and other public message boards to try and attract some freelance clients. There's definitely a market in tutoring lycéens for their exams in English. And, of course, hit the local language schools to see if they have posts or contract work available.
Cheers,
Bev