Teaching English in Indonesia is a popular choice for English teachers, and it can be fun and interesting, but the salaries are not the best in Asia (or even close). There is quite a high demand for teachers in this large country, but the situation changes frequently - pay attention to the weak rupiah. Speaking English gives status in Indonesia, with some celebrities showing off by throwing in English words and phrases when they speak. This helps teachers here, but the general level of English in Indonesia remains low.
There are TEFL jobs all over the country, perhaps not on all of the 17,508 islands that make up the country, but on many of them. However, most jobs are on Java and Sumatra, especially in the big cities such as in the capital, Jakarta, or Surabaya, Bandung and Yogjakarta. Bali is one of the hardest places to find work, although there is a little work teaching hotel staff English. And if you do find work in Bali, it will probably be in Denpasar - which is not paradise. The metropolitan area has a population of around 2 million, and the city has the usual big city problems of traffic, pollution and high cost of living. In general, TEFL jobs in Indonesia are available all year round.
A quiet part of Jakarta
The qualifications for a work visa for teaching English in Indonesia are quite flexible, depending on how much the school is prepared to pay in fines, or on their connections. There's a difference between the official line (degree in English, TEFL or a related subject) and what the private language schools accept. You can get a teaching job with just a degree and TEFL certificate, but the job may not be great.
Apparently, since 2003, there's been a regulation that English teachers must pass a test in Indonesian. This has not been enforced. There's now more talk of enforcing this, and forcing new teachers to take a TOEFL type test BEFORE they start. Time will tell if this comes about. There's also talk of introducing an HIV test - to be done in your home country before arrival.
As with everywhere, teaching English in Indonesia is easiest if you are a native speaker. As you browse the job ads online you will notice that many ads give as much information on the historical, cultural and touristic sights of the area as they do on the job itself. Indonesia does have many great things to do and see, but the pay is often low. It is enough to live on and travel a bit within the country.
Some teachers are earning 7-8 million rupiah a month, which is would make life hard in Jakarta, but of course this kind of discussion depends so much on your personal lifestyle. Double that would - of course - be much better, if you can find a job with this salary. The depreciating rupiah is a problem. Check for yourself - as any website will always be out-of-date on this.
Free accommodation is often provided, sometimes with utilities included. The accommodation is often shared. If you are well qualified and experienced, this could be a point for negotiation, and single accommodation may be possible to arrange. Flights are sometimes paid for as well.
Some jobs are advertised online, and it's possible to find work teaching English in Indonesia from outside the country. You can also find work on the spot, then travel to Singapore to sort out the work visa.
TEFL Paradise - but most jobs are in the city
Many of the cities in Indonesia have poor conditions, and it's common for the locals to call out when they see a foreigner on the street in any of the provincial cities. That is, anywhere outside of Jakarta.
Teaching English in Indonesia will generally mean teaching students from middle class families, often Chinese Indonesians. Many Indonesians finish school when they graduate from elementary school, due to the costs of education.
On the good side, the cost of living is low in Indonesia, and there's lots of good cheap fruit. Of course, there are some fantastic travel opportunities within the country, and in the region generally.
Of the 700+ languages in Indonesia, it's best to learn the national language - Indonesian - called Bahasa Indonesia within the country. It's spoken just about everywhere, and is easier to learn than many of the local languages. Of course, it still requires effort, and it's easy to live in Indonesia for years without speaking the language well.