Here's the true story of how I approached your assignment:
Note: Your research question at this point doesn't have to be set in stone! After some searching and reading, you will likely identify gaps or weaknesses in the current research that you want to explore.
Example
Can different types of music lead to different emotional responses? Find studies that have been done.
Step 1: Break up this research question into two or three main concepts. Ignore extraneous words.
Step 2: Conduct an initial search with these words, and quickly scan the results.
Step 3: Using information from your initial search, add synonyms, acronyms, and variant spellings.
(music) AND ("emotional response" OR feelings OR mood) AND (study)