Publication 535, Business Expenses
This publication discusses common business expenses and explains what is and is not deductible. The chapters cover general rules for deducting business expenses and specific expenses.
Publication 536, Net Operating Losses (NOLs) for Individuals, Estates, and Trusts
If your deductions for the year are more than your income for the year, you may have a net operating loss (NOL). This publication discusses NOLs for individuals, estates, and trusts.