It’s always a good idea to read something about your subject before writing.
Tips for reading to explore a subject
Of course, it never hurts to look at your textbook, assigned readings, or recommended readings cited by your instructor at the course Web site. You may find information relevant to your topic.
Related topics:
Annotating texts or visuals
Talking and listening
Listing
Clustering
Freewriting, keeping a journal, and blogging
Asking questions