Hello,

I am from France and read more into what you say and I indeed found out mostly things in French. That map is am administrative map of the Nazi government but also found in the Vichy government. As you read, at first the country was split in two the "Zone Occupée" (occupied zone) and the "Zone Libre" (free zone). However, that map is more detailed.

I. For the zones on the map :

• The A is the zone under the administration of the occupied Belgium, as part of the Nazi Belgium (puppet state).

• The C is the zone that is directly administrated by the Reich (which include the Alsace-Moselle area, the root of the ears between Germany and France since 1870', the "cause" of the three wars including WWI and WWII). That zone is considered to be a "core" of Germany.

• The D is the zone of "German repopulation" where refugies weren't allowed to come back to. That zone was meant to be populated by Germanic people ; only dutch, belgians and luxembourgers were allowed to come (and some french if they were rich and higher social class). The idea was for Hitler to create a new Thiois state used as a buffer between the Latin France/Europe and the Germanic Reich

It's important to note that some part of the zone C was simply forbidden, it was a demilitarized zone.

• The P zones are occupied zones where people were allowed to returned to, and are cut for administrative purposes.

• The M and B zones are the coastal zones meant to be a "wall" (M for Manche or Channel in English, and B for Bordeaux)

• The R zones are just the différent zones for the Vichy France

However, I'd advise to use a map like this one : https://images.app.goo.gl/aBd5RoqBqGAfnLQp8

It's way more detailed for a "control" zone. Because some part of the R1 and 2, and Corsica are in fact under Italian occupation.
You'll find again the "ligne de démarcation" which is in fact the border between the "2 Frances" which was very very hard to cross (although that changed through time to a point where of you weren't Jew, and if you'd get caught crossing that line, you'd need to pay a fee of "only" 200F -francs)

II. Coordination

It's important to know that only 1 to 3% of the French population was part of the resistance, that number is low for a lot of reasons which can be argued to be right or wrong for a long time. However, a major party of the population helped the resistance, you could even argue that you had a hard and soft resistance.

The resistance took some time to organize itself, and had issues to be fully organized. At first it was very locally, then the French first gathered together under a more institutionalised form, more military. My grandma's brother used to be in the south west after fleeing a camp in South France -Provence. He was a maquisard and he told me it was very "camaraderie" atmosphere, when his group finally got orders or new leadership under de Gaulle, nobody was laughing anymore, it was a real army atmosphere. They marched together to join other groups and became regiment of the resistance. They first march to the South to free Provence (that's where you could totally say that without resistance, the war would not be won, everybody talks about Normandy, but they didn't free much beside Normandy, Paris and the north east in direction of Berlin). After Provence, they march toward the North and the Rhin region, and toward Berlin. It was even a race : a race among of course the USSR and the West to be the first to win, but also between the French resistance and the Americans. Yeah, a race among the allies itself, all of that because you had different groups. De Gaulle managed to be the leader of the French resistance, but in the mean time, some resistance was under the command of the UK (de Gaulle being in England, he managed to still have some coordination and communications with the Brits), some other pocket of resistance was under the leadership of the Americans where the communication was very difficult with the rest. You can even find some resistance in France from Germany themselves, mostly communists of course.

No matter what, the resistance from any kind organized and communicated through radio a lot, but also through pigeon. The main one for the French was "Radio Londres" that would broadcast from London in a coded language to inform the resistance of what's going on, what's gonna happen in France and in all front. The other advantage of the resistance has been that the German did the mistake that the Americans will do in their modern wars (Vietnam, Afghanistan, Irak...) : The French knew their land, way more than the Germans. You can have a tank, but you won't do much if you have people running through the forest and the "maquis" (thus the name of "maquisards" for the resistance in the south) like it's their home (literally).

III. Where to read more

Unfortunately if you don't read French, it will be very difficult to know more. However to get what I wrote in this post I used what my great-uncle, a resistant, told me, but I also crossed different maps and website. If you can manage to read French, I would advise you the amazing website http://museedelaresistanceenligne.org/ It's a national website made to gather all the information about the resistance in France.

PS : I purposely didn't talk about the political aspect/engagement of the different parties in the war because it's a slippery slope in matter of politics. In France, while Americans are thanked for the helped, they are absolutely not seen as THE liberator of the country, a lot of other countries helped, without forgetting of course the major sacrifice that Algeria and the French Maghreb in general have done. De Gaulle even put his foot down after the war with the Americans by telling them to leave the country, he was very thankful but he refused the idea of American administration in France "to help the country," because "France has been helped by the Americans, the country is thankful, but at this time the rebuild and recovery of France has to be done by the French and no one else." He was mostly worried that the USA would try to turn France into a "base/foot hold" in Europe.

I hope my answer helped you cleared some dark spot :).