The best beach you've never been to
I spent one of the best months of my life teaching English in Nosara, Costa Rica during my senior year at university. The area, on the Pacific coast's Nicoya Peninsula, is wonderful because it isn't developed or overrun with tourists like other parts of CR. The locals are friendly, the bars are fun, and the arroz con pollo is delicious enough to eat night after night!
Every day, we'd hitch to the Playa Guiones, a few kilometers away. I'm not much of a beach person, but it was hard to tear myself away from Playa Guiones. The miles-long stretch of sand offered plenty of entertainment: walking, beach combing, spectacular views from the abandoned hotel on the point, tasty fish tacos at one of the nearby restaurants... and of course surfing. It's a great place to learn because it isn't crowded, the waves are substantial yet gentle, there's no reef or rocks, and it's shallow way out, so I was never afraid to go far to wait for the bigger waves.
We bought a board from Coconut Harry's surf shop and sold it back at the end of the month--cheaper than renting. Mostly we just played around, floating on the water and trying to catch waves. But I did also spring for a couple lessons. Having someone there to give you that extra push when a good wave comes along is sure helpful when you have the upper-body strength of a chihuahua, like I do!