Yes, you can get a deduction for charitable contribution for donating goods. If under $500, you don't have to fill out the Form 8283 to give more information on the donation; however, as always, you should have documentation should the tax return ever get questioned.
You need to get a receipt (so the unattended dropbox is not a way to get a deduction). You need an itemized list of what you donated, and the deduction value is the fair market value. For used items that means thrift store or garage sale value. For new items, it can be the cost you paid and the receipt is your documentation.