You should have Form 4562 in your return. It will be within your Schedule C if the assets were used in your business or Schedule E if the assets were used in your rental property, or Schedule F if they are Farm Assets. There should also be a depreciation report if your return contains depreciable assets.
Use Form 4562 to:
Claim your deduction for depreciation and amortization.
Make the election under section 179 to expense certain property.
Provide information on the business/investment use of automobiles and other listed property.
If you used TurboTax last year, you should have a Depreciation and Amortization Report for this business/rental activity. This is a TurboTax report and not an IRS form. See these instructions: How do I get a PDF of my return?
If your PDF copy doesn't include this worksheet, you'll need to access your prior year return to retrieve a complete set of forms & worksheets, including the depreciation report. See these instructions: How can I access my return after I've e-filed or printed it? (select your prior year return instead of current year). Then follow the link above to save your complete prior year return as a PDF.