The process for civil services exams will begin in the month of December with the advertisement for preliminary round (prelims). You may apply if you are sure you meet the eligibility criteria to appear for the Indian Administrative Services.
The preparations should begin in the right earnest. Since prelims are the elimination round you have to put in some extra efforts to remain in the reckoning for the subsequent rounds, including main examination.
There are two segments in the preliminary examination. One is General Knowledge (GK) and another is an optional paper. Both these are objective in character. You are supposed to score maximum possible marks to avoid elimination.
Coaching is not essential, but discipline and long hours of work are very crucial. The main exam has nine papers in all.