Paper 2 of commerce is totally theoretical and causes a lot of problem for many candidates due to non availability of good material. One advantage with this paper is that its syllabus overlaps with the Public Administration Paper-1 and thus helps in saving of time and better answer writing.
One important thing to get better marks in paper-2 is WRITING PRACTICE and use of examples from current affairs and corporate life. Let me first pin down source of reading for paper-2.
Organisation Theory & Behaviour
Organisation Theory & Behaviour- B.P. Singh & T.N. Chabra
Organisation Behaviour- L.M. Prasad
Human Resource Management
Human Resource Management- C.B.Gupta
Human Resource Management- K. Ashwathapa (Tata McGraw Hill)
Industrial Relations- T.N. Chabra & R.K.Suri
Dynamics of Industrial Relations- C.B. Mamoria & Satish Mamoria
Although above books are sufficient to cover the syllabus of UPSC still if you can get the RANKERS NOTES (available in the market) in addition to above books for paper-2, it will be helpful to you.
Ø Use of diagrams can increase the score in paper 2; diagram should be drawn with the use of Pencil only.
Ø Recent examples from corporate life & current affairs will fetch more marks.
Ø Writing practice will ensure better content.
Ø Answer should be given in simple and easy language
Ø No part of syllabus should be left.
Ø Help can also be taken from the MBA books, if available
Paper 2 is though theoretical; still more than 170 marks can be easily scored in it. I will advice candidates to put equal effort on both the papers as it is very easy to score more than 350 marks in commerce which can ensure your interview call and good rank in the civil service.
Best of Luck!