Most visitors reach Porto Santo from Madeira. The ferry from Funchal takes a little over two hours in normal conditions and is the classic approach, though the Atlantic can be choppy. Flights from Madeira are much shorter and useful if you are tight on time.
On the island, buses and taxis cover the basics, but a rental car, scooter, or bicycle gives you more freedom for viewpoints and quieter beach stretches. Vila Baleira and the main beach are easy to manage on foot.