First u need to be failiar with the exam pattern as Paper-1 contains English,G.K,Aptitude questions of 150 marks.
Paper-2 contains Financial Management & cost accounting ,tax & commercial laws questions for 300 marks.
paper1 is of objective type & paper2 is of descriptive type.
Check weightage of marks fro each topic & prepare accordingly.
Refer some good books,read Newspaper to be updated with current affairs & in the end give mock tests.