The word Nesso is also the Italian name for Nessus. Nessus is the centaur who was the ferryman on the river Euenos.
The C30 Bus line (the blue Como-Nesso-Bellagio line) regularly serves Nesso. It comes through about once an hour in each direction and has three stops in the town. The bus schedule can be found on the bus website  in pdf form.
The ferry and boat service on Lake Como does stop at Nesso. In high season about 4 times a day. It is a wonderful way to enter Nesso. The boat schedule can be found on the Navigazione website.
Like all the villages around Lake Como parking is at a premium. Day visitors can park free down the side of the church at the northern end of the village (about 20 spaces) or below the Tre Rose (see below) on the lake side of the main road.
Like many of the roads around the lake, the roads in Nesso are very narrow and frequented by full sized buses and apparently suicidal motorcyclists. Try not to walk on the road whenever possible. The beautiful cobbled walking paths either below or above the road provide an excellent alternative.
The lake water in Nesso is continuous provided by fresh water that comes from the mountains and enteres the lake by the tremendous and famous waterfall L' Orrido di Nesso. Because of this fresh and clean source, Nesso has clean swimming water. You can enter the lake for a swim at several points. At the 2 bridges you will find steps to enter the water. Or you even can jump from the bridges. The water is deep enough. And near the church is a small public beach.