I have the perfect organizations for you & thank you for your interest in helping El Salvador!
Funzel is an amazing organization catering to the welfare & well being of wildlife on land & in the ocean. The big issue right now is preservation, conservation & liberation of the endangered sea turtles. This is their nesting season & egg retrieval is a priority as well as education of the Salvadoran people regarding the importance of non-consumption & non-selling of tortuga eggs! Funzel & its volunteers are relentless in their efforts to preserve all species through rescue & release.
Here is their Facebook page, http://www.facebook.com/funzelsv.org. My husband & I do everything we can to support Funzel through monetary donations & our time. Last year I released over 1800 new sea turtle hatchlings which was a phenomenal & unforgettable experience! You can contact Funzel through Facebook for more information.
There are other organizations in El Salvador as well including Save the Children, Habitat for Humanity ( http://www.habitatelsalvador.org.sv/ ), Violence Against Women, World Vision, etc. If you Google non-profit organizations in El Salvador you will get some ideas what is best for you & how to go about it!
As a Canadian now living in El Salvador, I thank you again for your desire to volunteer in this incredible country!
Salud! ..........Cathy :D