In general the Island of La Gomera is sparsely populated outside the main towns so public transport is limited. Since many of the most interesting sites tend to be a little off the beaten track hiring a car is probably the most convenient approach.
If you do hire a car a good map is a must and it is usually worth while to get an up to date guide book if you plan to visit regions not covered by your own research.
For those of you from countries where people drive on the left it is worth remembering that in Spain people drive on the right and it takes a bit of getting used too. Also bear in mind that many of the rental cars are manual gearshifts so if you prefer automatic cars make sure to specify when renting.
La Gomera's main towns are connect by regular bus services . The ferry companies Fred Olsen and Armas provide services between San Sebastian and Los Cristanos on Tenerife.