Coming into town, the bus stops in front of the train station. You then walk down Corso Umberto to the town.
Going back to the marina, you pick up the bus on Via Cristoforo Colombo on the east side of the road, just past the big arch.
Bus tickets purchased on the bus cost €1.50 but you can buy them for €0.85 at coffee shops and tobacconists near the train station. Worthwhile to stock up on a few tickets, because you can only buy them on the bus at the marina end for €1.50.
Don't forget to validate the ticket by inserting it into the machine on the bus to get it stamped.