Quality is much more important than quantity.
It is wise to begin research on your paper early in the term. Be sure the library has the materials you will need. Unavailability of sources is not an acceptable excuse for a poorly researched paper. If you cannot obtain key source materials, you should change your topic and this is much easier to do if you check on the availability of source materials early in the term. Your paper should show evidence, where appropriate, of your familiarity with the content of the required readings and the lectures in this course.