US to another country

Are there any agencies that will help getting a united states citizen work in another country....a poor country where we can help..I remember going to El Salvador when I was 15 and there was an American nurse who was there for a year and I thought that I would love to do that one day...well that day is here but I dont know how to go about it...do we need to call actual hospitals in the country of choice....PLEASE HELP!!!