Some popular books recommended for UPSC preparation include "Indian Polity" by M. Laxmikanth for polity, "Indian History" by Romila Thapar for history, and "Economic Survey" for economic concepts. Additional key resources are "Certificate Physical and Human Geography" by G. C. Leong for geography and "Environment and Ecology" by Subramanian for environmental studies. For current affairs, "Manorama Yearbook" and "The Hindu" newspaper are frequently recommended. Candidates often refer to NCERT textbooks for foundational knowledge, particularly for subjects like science and social studies.