The key to planning a great French trip is a great French travel book. It not only can help you establish an itinerary, but you can also decide on lodging, dining and attractions for while you are there. I never travel without a couple in my bag to help me decide what to do. Here are the most indispensable travel guides.
Michelin's Green Guide is the absolute bible of French travel. It is especially useful if you aren't quite sure where to stop along the route (it has ratings of locations such as "worth a journey" or "interesting.") The Michelin guides are probably more reliable than any others when it comes to a frank review. A must-have!
France Eyewitness Travel Guide is one of the best overall books about this country around. The best part of this book is all of the pictures, which fill much of each page. The book also has a "visual glossary" of territorial cuisine, as well as floor plans for various attractions.
This France guidebook is light on the images, but heavy on the details and content. This is an ideal choice if you want historical information about French destinations, as well as exhaustive listings of lodging, dining and attractions in France.
Rick Steves tells it like it is, and I think his guide has loads of practical and useful information, not just about the basics like lodging, but also about a country's culture and what to expect. What is great is he will tell you about underrated destinations you might never visit, and the overrated ones that are a waste of time.