Answer: When does it happen? Where does it happen? How does it happen?
Other books, writing prompts, conversations with friends and family. Primarily when conducting research you're looking for information from primary sources. By conducting research you are allowing yourself to get a grasp on what you're about to write about. Which allows your writing project to be accurate. You should prepare before beginning research by having an idea about what you want to write about, as well as a short list of accurate sources.