The sale will be treated as a long term capital gain. You will use the basis that your mother had in the home, which means what she paid for the home plus any capital improvements. You will take the sale price minus closing costs minus your basis and that will determine your taxable gain. You will claim one half of the gain and your brother will claim the other half. The federal tax rate on this gain will most likely be 15% plus your state taxes.Please ask any follow up questions.