Public Buses in Provence
Bus services along the coast are pretty good (as is the coastal train service), making it easy to visit places from Cannes to Monaco. Travelling inland is not quite as simple as the bus services are infrequent and not that extensive.
You can try looking at the central website that provides details of these lines, but note that it is not exactly straightforward to use! Look for the 'Télécharger la carte de réseau LER' text to see a map of the bus routes available. Watch out for bus lines named 'Ligne Scolaire - these are school buses only, and not for public use.