You really want to take a look at Elizabeth David's books. There's a pre-suppostion with some of them that you can already cook, though.
Look for people with strong associations to regions, like Roger Verge. His books are wonderful. Again, you want to be pretty good going in.
Madeline Kammins -- out of print, I'm sure -- is great if you can find her.
One of the problems with regional cooking is fresh, quality, regional ingredients. Provencal is all very well and good if you live in California, but pretty tough most other places.
It might be more helpful to organize your search around ideas like "bourgeois" and "impromptu," rather than regional. Also, look at nearby countries. There's a lot of cross-over between Alsatian and German, for instance. The whole northern Med has a lot in common. Spanish, French, Italian, what the heck? So much is alla time same same. Hope you like grilled fish.
Chris Belgium can probably help you with northern France, especially the western part of the country. Belgian food has a lot in common with Normandy -- but better beer in Belgium. Much better beer. Much much better beer. Chris may know about some English books and websites, God knows he's sufficiently bilingual.
Google. You can get lots of regional dish names from simple search terms. For instance you could try "brittany cuisine," "brittany dishes," and "brittany food." Once you've got the names of foods which look good to you, start looking for recipes. The recipes which look best usually are best. The recipes which look best to you, are most likely those you'll like, and those which don't look good you probably won't like. Funny how that works, eh? If you already don't like kidneys, chances are you won't like them just because some joker calls them rognon and serves them in a Calvados reduction [drooling smilie].
Read French? Big help. Once you've got the dish names, just add recette.
Rule of thumb: An obscene amount of butter is always a good sign. If your arteries don't slam shut when you first see the recipe, it's probably not that good.