Literary sources that aid in preparing for the sociology optional paper include textbooks like "Sociology: Themes and Perspectives" by Haralambos, and "Sociology of India" by M.N. Srinivas. Journals such as the "Indian Journal of Sociology" and various research papers enhance the understanding of complex theories and contemporary sociological issues. Online platforms like edX or Coursera can also provide valuable resources. Additionally, using summaries and past year questions can aid in grasping key concepts and thematic approaches critical for the exam.