Where do I include siding installed in Deductions & Credits?

[xmasbaby0]

Siding on what?   If it was for your own home, you cannot deduct repairs or improvements to your own home. You save your records of the expense for someday when you sell the house.

[DoninGA]

If this was installed on a personal residence, not on a rental or a business, it is not deductible on a tax return.  You can enter the cost of the improvement to the basis of the home when it is sold.