Recommended books for UPSC preparation vary by subject, but some essential ones include NCERT textbooks for fundamental concepts, and "Indian Polity" by M. Laxmikanth for polity knowledge. "Economic Survey" and "Budget" are crucial for understanding the economy, while "Historical Atlas of India" can enhance historical insight. For environmental studies, "Shankar IAS Environment" is highly recommended. Additionally, "Indian Art and Culture" by Nitin Singhania is valuable for cultural topics. It's best to refer to multiple sources for a well-rounded understanding of the syllabus.