Hi and welcome to the forum.

Basically, as an expat in France, you'll be taxed just like any other legal resident of France - which means on your worldwide income. France has tax treaties with a variety of countries to avoid double taxation of various sorts of income you're likely to be receiving back at home while resident in France.

There is an overview of French taxation available in English from the French tax authorities here: http://www.impots.gouv.fr/portal/dep...ptive_1006.pdf
Just be aware that this is about 2 or 3 years old and some details (especially the rates) have changed. A more up to date overview (with less detail) is available from the AngloInfo website here: French Income Tax and Being Tax Resident in France - French Riviera - AngloINFO Riviera (France)

Give a shout if you have specific questions about your situation. If we can't answer them directly, we can at least point you in the right direction for an authoritative response. (How's your French, by the way? It's rare for the French Fisc to translate forms or instructions into any other language.)
Cheers,
Bev