It is good that you are thinking for PG entrance from 2nd year MBBS itself. As you have lots of time for pg entrance, you can plan your studies according to needs of exam.
1.Coaching Institute- You can join any coaching institute in your city like DAMS,PG-DIAMS, Dr. Bhatia etc. They will provide you not only notes and study material but a vision to succeed in PG entrance.
2. Concept building-Do focus on basics of every subject like pharmacology, pathology etc because examiner do not expect you to have pg level knowledge but to have basic concepts of MBBS.
3. Smart Study-Plan your study on priority basis. Choose subject weightage wise.