I've heard that the French Resistance basically didn't do much until after the Allies began landing in Europe (I'm assuming D-Day but possibly also after the invasion of Italy) and I've also heard that they actively fought the German occupation throughout the war after France's capitulation. Which if these characterizations is closer to the truth?
The French Resistance provided valuable Intel for the Allies prior to the invasion, although their resistance during the invasion was met with brutal reprisal such as at Oradour sur Glane. Then Vercors Massif was taken over by the French resistance in southern France, before being retaken by German forces in the summer of 1944. The Maquis also aided the invasion of southern France, and the resistance subsequently provided man power to the French army once France was liberated.