Choose a topic that interests you within the assignment guidelines.
Generally, good research questions...
Can't be answered with yes or no
"What are the health effects of second hand smoking in children?" is better than "Does smoking have a negative impact on health?"
Are broad enough you can find information
"What is the impact of tobacco advertisements on tobacco sales?" is better than "What is the impact of tobacco advertisements on sales in Laramie?"
Are narrow enough you can start to answer them
"What are the impacts of racism on health care in the United States?" is better than "What are the impacts of racism in the United States?"
Where you search depends on your topic and what you need to know.
Need a little more detail? Search for books on your topic. You don't have to read the whole thing!