Hi Rebekah,
I absolutely love your plan to get to the heart of South America with volunteer work. As you may know I stayed 6 weeks in a street child care center called CEAMAC in the suburbs of Salvador da Bahia, Brazil. To start with, I was the first volunteer ever in the center. I got their address by going to the tourist office in Salvador. Although I have some great pictures of the center and the kids I'm very reluctant to post them on my site. There is one picture I used on my page about
volunteering in South America.
I can highly recommend the
Free and low-cost volunteer work in South America website for a very detailed overview of South America volunteer organizations. The website is run by Steve McElhinney.
In some organizations you don't get payed but you do get accommodation and food, in others you pay to stay and help out. Hopefully more people are able to share some information about organizations offering volunteer work in South America.
Please do ask more questions if something is still bugging you. I'll do my best to help you out.
Best wishes,
Mark