Before you start searching try to clarify "what you really need to find". Ask yourself these questions:
Once you have a clearer picture of what you need, you can then examine your assignment topic, break it down into small components (concepts and keywords) to make your search more efficient.
This video outlines the mind-mapping technique, to get you from broad ideas to more narrow topics, and to help you see different approaches and questions
A topic is NOT a research question.
Example:
Topic: Solid waste & recycling in Japan
Possible Question: What factors have led to Japan's successful e-waste recycling programs?
Possible Question: Which features of Japan's solid waste management policies, laws, and implementation could be transferred to other national and cultural contexts for e-waste reduction? What bad practices could be avoided?
How to go from topic to questions:
1. Do some background reading (encyclopedias, short magazine or news articles)
2. List questions & answers you may already have
3. Think about your questions and what answers you have.
4. Try to make a few clear questions, that are based on some of the ideas (theories, words, methods) that you have learned in your course.
5. Try to choose one of the questions, not too wide & not too narrow.
6. Be prepared for your question to change.
Based on: "How do I get from a topic to a research question" - from Cambridge LibAnswers