How do I delete items off of depreciation? Where do I enter new items for depreciation?

You don't delete depreciable items, ever. Even if fully depreciated. Is this for rental income on SCH E? Or self-employment income on SCH C?

schedule C, may I know why not? i was thinking that my list was getting terribly long and that I should start removing some items that have been lost/broken.

You can't just delete an item when it's fully depreciated, because in the tax year you sell or otherwise dispose of that asset, you are required to recapture all depreciation and pay taxes on it, in the tax year of sale or disposition.
Many incorrectly believe that depreciation is a deduction that is permanent and forever. It's not.

You can add or delete assets for depreciation by following these steps:

1. Click on Income and Expenses and then click the Start/Revisit box in the Self-Employment section.
2. If you have already entered some assets, scroll to the EXPENSES section and click the Edit box next to Assets.
   
3. On the screen, Do you want to go directly to your asset summary? mark the Yes radio button and click Continue.
4. On the  Business Asset Summary screen, click Edit next to the asset you want to change or stopped using for business.  You don't want to ever just delete the asset.
   
5. If you want to add assets, click the link at the bottom of the table, Add an Asset.

How do I end an asset in depreciation