First you have to complete ncert books of history geography economic and civics of class 6 to 12 and then read newspaper daily and current affairs

First of all go through the syllabus of upsc ..it would be better to have a hard copy of it ..just go through it ie to have a read . Now as to strt from basics then NCERT the only basic developer. yes its correct one to go through ncerts bt make sure dont lose sleep over it ..take it as a concept builder . The most important is current affairs now first of all instead of going through too many sources..one stop source to have a better understanding of how to deal a issues just have a reading of the hindu and a monthly magazine, one note is don't panic as its new for all bt i am so sure as u will have a habit it will make u have ease in the future or for yur help you could see any of the analysis of hindu available in YouTube. I would suggest if you are English medium student then see RAU IAS and if hindi then ONLY IAS ..while you read hindu make sure to find the meaning of the vocab as it will improve your language. Further after ncerts then move to standerd books of GS 1 to 4 ..meanwhile make sure of seeing your syllabus as well as previous year questions. Books such as LAXMIKANT for polity and more as such just google it you will get standerd books .if any other query just ask . i have given a lot bt still if any ..u can have your doubts. All the best..