First, create a working thesis.
What interests you?
What is a suitable topic for your assignment?
Rephrase your topic as a question. That question is your working thesis.
Your research should focus on answering that question.
Refine your search
If you are not finding enough information, your question may be too narrow.
Consider broadening it by exploring related issues or expanding the keyword search by using synonyms.
If you are finding too much information, your question may be too broad.
Consider narrowing it by adding another element to the topic, limit to certain time period, geographic location, or population.