Mild temperatures make fall (September and October) and spring the best times of the year to see this part of Italy. The summer crowds are gone and it's a good time to connect with the locals and discover the real Amalfi Coast.
Check out these links for what to see and do
Amalfi Coast http://www.travelandleisure.com/travel-guide/naples-amalfi-coast
Unashamed Sorrento http://www.lonelyplanet.com/italy/campania/sorrento
Amalfi, Positano & Sorrento 7 Night Vacation Package