The opportunities to teach English in Costa Rica are quite good, as learning English is seen as important in improving job prospects. Most of the job opportunities are in San Jose, the capital. Although most of the language schools are located in San Jose, there are also language schools in the smaller cities. There are a few jobs teaching English on the beach - or at least not too far from it. However, the jobs in the coastal towns are relatively few and the competition for jobs there is severe, resulting in lower salaries. In fact, if you want to teach English in Costa Rica, you should have no expectation of making any money, beyond basic living expenses.
If you want to teach English in Costa Rica, you are best looking for work once you are in the country, as is usual when teaching English overseas. Jobs are sometimes advertised in La Nacion, and in the English language online newspapers, Tico Times and AM Costa Rica.
Online searches will come up with lists of schools in Costa Rica. One such list is here on LA Job List Another source of information on Costa Rica is the Yahoo group 'Cost Rica Living.'
A neat appearance is expected by employers. You need a degree to be employed legally. Make sure it is legalized before you leave your country. Native speakers are preferred. TEFL certificates are asked for by some employers, but are not absolutely necessary; although, if you apply from abroad, TEFL certification would be useful.
There are a number of institutes which offer TEFL certificate courses in Costa Rica, which may be a good way to explore job opportunities while you are taking your certificate. American English is generally preferred, but native speakers from other countries should be able to find work teaching English in Costa Rica.
For many nationalities, no visa is required to enter the country as a tourist, and 90 days are given. However, to teach English in Costa Rica you need a work visa, although some teachers work illegally. Once you find a job, then the language school should do the paperwork for the work visa. You may have to leave the country during the process, then re-enter. As mentioned above, a degree required to get a work visa.
Pay is low for teaching English in Costa Rica. US$ 6-9 an hour. Monthly salaries range from $400-$1,000, and even though the cost of living is low, you should not expect to save much money. Don't expect to be able to pay off your student loans, for example, try teaching English in Korea for that. But you can earn enough to live in the country - if you don't mind sharing accommodation.
The school year begins in January and ends in December. October/November is a good time to contact schools. You could make preliminary enquiries at this time, before you arrive in late December or early January. The quietest time is September-November. However, private language schools hire all year, depending on their requirements. As is common throughout the TESOL world, split shifts and weekend work are common.
There are some concerns for personal safety in the country. There has been a rise in crime in recent years. San Jose is dangerous at night, and many people stay inside once it get dark, because of this. Outside of the capital, the situation is better.
Costa Rica - outside of San Jose - is a beautiful country. There are good opportunities to spend time hiking in tropical forests, relaxing on the beach, or white water rafting; although traveling to the beautiful places, assuming you work in San Jose, may become a little tiring. Buses are cheap in the country.
Costa Rica is also a good place to study Spanish. A little more expensive than studying in Guatamala, but the standard of living is higher in Costa Rica.
A view of San Jose