Aside from teaching or tutoring English, opportunities for employment are few, low-paying and usually illegal. Even tutoring, despite good hourly rates, is rarely remunerative because it takes time to build up a clientele. The best opportunities for teaching English are in the larger cities, and, although you won't save much, it will allow you to stick around longer. Other work opportunities may exist for skilled guides or in restaurants and bars catering to travelers. Many people find work at foreign-owned lodges and inns.
There are several excellent online resources, including the following:
Association of American Schools in South America (www.aassa.com) Places accredited teachers in many academic subjects in schools throughout South America.
Dave's ESL Café (www.eslcafe.com) Loads of message boards, job boards, teaching ideas, information, links and more.
EnglishClub.com (www.englishclub.com) Great resource for ESL teachers and students.
TEFL Net (www.tefl.net) This is another useful online resource for teachers from the creators of EnglishClub.com.