As there are many books available in the market but it is advisable to follow "BHU Banaras Hindu University B. Com. Bachelor of Commerce Entrance Exam (English) Editions along with previous year papers as these would be the best sources to crack the exam with flying colors.
You can get the papers from below link as well -
BHUET Sample Papers
Good Luck!!!
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile