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.
A topic is NOT a research question.
Example:
Topic: Status of indigenous land claims in international law.
Possible Question: Has the respect for indigenous people's land rights improved since the UN Declaration on the Rights of Indigenous Peoples (UNDRIP) was passed in 2007?
Possible Question: What has been the affect of the UN Declaration on the Rights of Indigenous People's on land disputes in Brazil, Canada, and the USA.
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
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