Hello,

In order to initiate your preparation for Preliminary exam of UPSC, you need to well acquinted with the following exam pattern and syllabus;

Preliminary is MCQs based exam, it has two papers and each one consists of 200 marks,its numbers ain't added to final list, you just need to score the required cut offs against your category.

First is GS Paper-I which consists of the following topic such as History of India and Indian national movement, Indian and World geography, Economic and social development- sustainable development, poverty,inclusion demographics, social sector initiatives etc,Indian polity and governance-constitution,political system,Current Events nationally and Internationally, General Science,General Issues on environmental ecology,biodiversity and climate change. you just need to score the required cut offs against your category.

Second Paper is CSAT which is qualifying by nature,you need to score merely 33% which is 66 marks out of 200, it includes following topics such as basic numeracy, comprehension, logical reasoning and analytical ability, general mental ability, decision making and problem solving, interpersonal skills including communication skills.

I n order to initiate your preparation, the first and most important step is to be well acquainted with UPSC Syllabus as aforementioned, learn it by heart as this will enable you to know what to read and what to skip.

To cover such a humongous syllabus you will have to make a timetable,set targets on a daily,weekly and monthly basis,that's the only way to complete this extensive syllabus.

Newspaper reading is equally vital part of preparation, you can start with any newspaper like The Hindu, or Indian Express on a regular basis to be updated as well as gaining knowledge which shall be highly useful to you in future exam preparation part. Put a more emphasis on editorial part, it will not only broaden your perspective but help a lot in answer writing,and make sure whatever opinion you form it should be well balanced. You can also make notes of this,it'll be very useful in answer writing.

When it comes to reading books ,start with basics, for each subject, you can do with NCERTs for this. This will build your foundation strong,as you progress, move on to other relevant books as mentioned below;

For Prelims, you can refer the following books:

History ;

NCERT Class XI and XII
India's Struggle for Independence by Bipin Chandra
For Indian Culture, refer art and culture by Nitin Singhania

Geography ;

NCERT Class VI to XII
GC Leong's Physical Geography
World Atlas

Economics ;

NCERT Class XI
Indian Economy by Ramesh Singh

International Relations & Polity ;

NCERT XII Political Science with current affairs
Indian Polity by Laxmikanth

CSAT ;

Verbal and Non-Verbal Reasoning by RS Agarwal
M Tyra's Quicker Maths

Remember to keep your resources minimal, read one book many a times instead of many a book one time, as you have to retain so much of information so rely on only limited yet trustworthy resources and revision is the only key for remembrance.

Practice previous year question paper which you can get from the official website of UPSC,

Also, apply mock papers, and test series which you can get it from any of the sites exclusively dedicated to UPSC preparation to enable you analyze your preparation level, and improve upon your speed, time management skills.