any suggestions on the best maps for planning and driving?
You can’t go wrong with Michelin maps. Here’s the link to their website: https://www.viamichelin.com/web/Maps. They even sell guidebooks geared towards those who drive: https://travelguide.michelin.com/.
When we picked up our car, we asked for any map that our rental company could provide, they directed us to a bookstore down the road. Having a Michelin map before you receive your keys will be a good thing.
Michelin maps for sure. The country map plus detail maps for any areas/towns you will visit or even go through. Get a tablet and download an off-line map program capable of plotting GPS info. Have your navigator practice with it at home. Downtown Athens at rush hour is not the time to refer to a paper map! (Been there, done that - ugh). And your pre-planned details will go bye-bye more often than not.