If you would like to exchange dollars (USD) into Costa’s Rica’s local currency, Colones, you can easily find the most recent conversion rate through Google. However, you do not need to exchange USD into Colones, as the majority of vendors in Costa Rica take USD.
For more details on exchanging currency, check out this article.
Costa Rica has a tropical climate year-round. There are two distinctive seasons--the “high season”, and the “green season”. The high season lasts from December/January - May/June (depending on where in the country you are visiting). The weather is at its peak during the high season, and is a great time to explore local beaches. The green season (known locally as winter) tends to be much rainier, and is the perfect time to explore Costa Rica’s luscious rainforests.
Costa Rica has the same sockets as the United States. However, many eco-friendly resorts often don't have a socket for a grounding prong, so it is recommended to bring an adapter as a precaution depending on the venue you pick.
Always check the US Department of State website for full details regarding visa requirements.