Since we are talking about social sciences research here, the most likely ethical concerns have to do with the fact that you are doing research on human subjects. Your research and the way that it is presented and implemented may have an impact on the lives of actual people.
Because of this, it is important to have been careful about the ethics of the project from an early stage. You have to be sure that you are not presenting your research in any way that will allow people reading your findings to identify any of your subjects. You have to make sure that your research will not be used in ways that will hurt people who have spoken to you in confidence.
Basically, it is important to be as sure as possible that your research will not be reported or implemented in ways that harm your subjects.