You enter all of the information about your brother just as if he were still alive (although you will want to use an address that the IRS can actually reach you at). After you have entered the information about him personally the system will ask if he is deceased and you will say yes. Then it will ask for his date of death. After you enter that everything else is the same as any tax return until the end when the system may have more instructions for you. But TurboTax will walk you through it.