Which book guides me regarding the rulings of buying and selling?

We thank you for your eagerness to know what is permissible and what is forbidden, for ignorance of the rulings of Islamic law can lead to falling into what is prohibited, especially in the chapter of sales. Umar, may Allah be pleased with him, used to strike those who did not know the rulings of buying and selling and say: "No one should sell in our market except one who has understood our religion." Contemporary jurists and scholars have dedicated a separate chapter to the rulings of sales. We advise you to acquire books by contemporary scholars that address new issues. And if you wish to embark on a transaction before knowing its ruling, then ask the people of knowledge, in fulfillment of His, the Almighty’s, saying: "So ask the people of the message if you do not know."