NatureAir has two daily flights to and from San José for about US$149 one way. It offers discounts based on the weight of your luggage.
Local buses depart from the pulpería (corner grocery store) by the soccer field. Traroc buses depart for Nicoya (US$3.60, two hours) at 5am, 7am, noon and 3pm. To get to Sámara, take any bus out of Nosara and ask the driver to drop you off at 'la bomba de Sámara' (Sámara gas station). From there, flag down one of the buses traveling from Nicoya to Sámara.
From Nicoya, a paved road leads toward Playa Sámara. About 5km before Sámara, turn onto a windy, bumpy (and, in the dry season, dusty) dirt road to Nosara village (4WD recommended). This road was being paved at the time of research, so cross your fingers, folks. It’s also possible (in the dry season) to drive north to Ostional, Junquillal and Paraíso, though you’ll have to ford a few rivers. Ask around before trying this in the rainy season, when Río Nosara becomes impassable.
There are two gas stations in Nosara village, and a couple of rental car agencies in the Nosara area: