Though I am still in first year, yet I would like to share my views on this particular question. Frankly speaking, doing good in NEXT PG is my aim. So I try to collect information about it as much as I can. Till now I have watched interviews of NEET PG and AIIMS PG toppers, read many answers on quora regarding this topic and have found following things which were common in them:-
A. First and second year subjects of mbbs syllabus are pre and paraclinical ones. In order to understand the clinical part well we need to have strong concepts and hold on these subjects. So it is advised to try to understand concepts of these subjects as much as possible. For that one can refer to resources like DR. Najeeb lectures,YouTube etc to understand the topics well.
B. Mostly it is advised to follow standard books during your MBBS to have good concepts and it will be helpful in pg too. I am also a follower of this postulate. Although I have seen toppers like Dr Shiv Kumar AIR 1 NEET PG 2020, Dr. Aakansha Naik AIR 13 NEET PG 2020 etc who have stated in their interviews that they never followed standard books in their mbbs. So it is advised to read those books through which you understand the concepts easily.