The syllabus for UPSC prelims is:
Paper - I
Current events of national and international importance
- Current affairs – sanssad tv, the Hindu, the Indian express. Your regional news channel and paper.
History of India and Indian National Movement
- NCERT + Newspaper
- Art and Culture Current Affairs
Indian and World Geography
Physical, Social, Economic Geography of India and the World
https://www.incredibleindia.org/content/incredible-india-v2/en/experiences/heritage.html#
https://knowindia.india.gov.in/
Indian Polity and Governance
Constitution, Political System, Panchayati Raj, Public Policy, Rights Issues, etc.
Economic and Social Development
Sustainable Development, Poverty, Inclusion, Demographics, Social Sector Initiatives, etc.
https://www.indiabudget.gov.in/economicsurvey/
Science
General issues on Environmental ecology, Bio-diversity and Climate Change - that do not require subject specialization.
General Science.
https://agriwelfare.gov.in/en/Agricultural_Statistics_at_a_Glance
https://moef.gov.in/moef/index.html
Common Resources:
- Previous Year Question Papers
- Overall basis – NCERTs
- PIB (Press Information Bureau) -https://pib.gov.in/indexd.aspx#
- News Channels - Sansad tv, Your regional news channel
- Newspaper - The Hindu / The Indian express and your regional news channel and paper
Paper - II
- Comprehension;
- Interpersonal skills including communication skills;
- Logical reasoning and analytical ability;
- Decision making and problem solving;
- General mental ability;
- Basic numeracy (numbers and their relations, orders of magnitude, etc.) (Class X level),
- Data interpretation (charts, graphs, tables, data sufficiency etc. — Class X level);
Sources:
Previous Year Question paper – The most important
For Basics :
- A Modern Approach to Verbal and Non-Verbal Reasoning by R.S. Aggrawal
- Analytical Reasoning- M K Pandey
I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times - Bruce Lee