Best route from Atlanta to Maine?

I don't know about pet friendly, but I can recommend the following:
Marblehead observe lobstermen on the dock
Len Libby Candies - Home of the Life Size Chocolate Moose!, Scarborough, ME
Kennebunkport Motor Lodge
Claddagh Motel & Suites, Rockport, ME
Red's Sandwich Shop in Salem, MA has an awesome breakfast 
Moosehead Lake for rest and relaxation 
L.L. Bean Flagship Store Flagship store in Freeport, ME