What is the adjusting entry for depreciation?

When you do the entry it is:

Debit Depreciation Expense for the amount
Credit Accumulated Depreciation - (the appropriate PP&E account) for the amount

Depreciation expense (DEBIT)
Allowance for Depreciation (CREDIT).

If Trial Balance shows Allowance for Dep. (CR) balance than less with Adjustment amount.

If Trial Balance shows Allownace for Dep. (DR) balance than add with Adjustment amouint.