From the site:
"Learning Bahasa Indonesia
The best time to start learning Bahasa Indonesia is before you even make your move to Indonesia, however it may be difficult to find language materials in your home country. Ask your sponsoring company to help you obtain tapes and books several months before you move, so that you can start becoming used to the sound of the language.
Formal Courses
Soon after your arrival in Indonesia, make it a priority to register for a Bahasa Indonesia course. There are several excellent schools and community organizations in Jakarta (and other cities) which have comprehensive, structured programs to help you begin learning Indonesian. Learning Indonesian properly from the beginning can not be stressed enough.
Another advantage of signing up for a course is that it's a great place to meet other newcomers and make friends. The people that you will be taking the course with will also be facing many of the settling in and adjustments challenges that you too face as a newcomer.
Tutors
Others opt for private lessons in their home or office from private tutors. This option tends to be the most expensive, and there is little control over the quality of the curriculum and instruction. Even though the tutor may come highly recommended from others, that does not ensure the quality of their instruction. You may, however, find it useful to meet with a tutor for a period after you have completed several levels of a formal course. That way they can help you with any special problems or requirements you may have.
Self-Taught Bahasa Indonesia
Some expats opt to learn Bahasa Indonesia on their own. Excellent books to learn Bahasa Indonesia are available in bookstores around Jakarta. Once you are in Indonesia, practice your fledgling Indonesian with your servants, driver, vendors and people you meet in the stores and social encounters. The diligent will quickly pick up enough Bahasa Indonesia to feel comfortable interacting with Indonesians on a daily basis.
Pen Pals and Indonesian Friends
True fluency in a language requires active use of the language. Many expats find it helpful to get a pen pal or have a "language buddy" relationship with an Indonesian where you help each other to learn a desired languages by sharing your skills. This can be as simple as setting up a time to meet once or twice a week where you focus on learning language and developing a friendship over coffee or email each other any questions you have about the language.
Many Indonesians want to learn English, or French, or German ... so if you want to learn Bahasa Indonesia, offer to "trade" skills by investing time in each other's language studies. Obviously you can pay a private tutor to do the same thing, but this type of a relationship is based on mutual benefit and doesn't involve payment. One time you focus on helping the expat to learn Indonesian, and the next time you meet you focus on helping the Indonesian to learn the foreign language."
Comments
This site has some audio recordings of some basic words and phrases for Bahasa Indonesia. It also has lots of cultural information and links to other resources.