If you are in Las Terrenas, or are willing to relocate there .. I know that the
Fundacion Mahatma Gandhi
has summer camps and some ongoing programs and runs a community library. They bring in foreign volunteers, and ask a contribution for those who stay at their house but there are no paid staff so you don't actually pay to volunteer. They also make use of longer term volunteers who come down.
The only drawback is that LT is not a cheap place to live, but, of course, no where on the north coast is a cheap place to live, what am I thinking
any way, they are a good group.... Jose and Annette are dedicated and competent.. Jose is a Professor at the U of MD (distance learning) and Annette also has a Master's degree so they are both really qualified. Jose is Dominican American and moved back here five years ago. Very dedicated to helping the people there.
Just get in touch with them and let them know what you want to do and I am sure that they will find something for you if they can.