Common sources for UPSC General Studies preparation include a range of materials that candidates should utilize for comprehensive learning. Notable textbooks include NCERT books that provide solid foundational knowledge across subjects. Reference books authored by recognized experts, such as 'Indian Polity' by M. Laxmikanth and 'Introduction to the Constitution of India' by D.D. Basu, are also crucial. Current affairs can be covered through prominent newspapers and monthly magazines like 'Yojana' and 'Kurukshetra.' Online platforms offering video lectures and notes, as well as UPSC-specific coaching institutes, can provide additional support and resources essential for effective exam preparation.