You will start with an idea for a topic and will probably need to explore some sources and learn more about that topic in order to develop a good research question. A good research question is:
The question should be specific enough that you can provide an answer in the length of the assignment requirements but not so specific that there are no sources available to help you answer the question. Topics that are too broad will be unmanageable because you will find too much information to adequately answer the question.
While you want your question to be somewhat unique so that you are not simply restating what others have already written, you also want to make sure your question is something for which you can find information.
Your question should not have a simple yes or no answer. It also should not be something that can be answered with only facts (for example, "How many immigrants have entered the United States in the past 20 years?") Your question should require you to find several different pieces of information and consider how they work together to create a well-supported answer.
The answer to your question should be something that others could reasonably disagree with by considering different perspectives or evidence. You may even want to present counter-arguments in your paper to demonstrate why your answer is the best one.