Donations are only deductible if they are made by, to or through a registered tax exempt organization (mostly 501(c)(3) but there are a few more types) or if made to a state or local government or branch of government. You would need a letter from the organization acknowledging your service, although the letter does not have to provide the dollar value of your assistance.
Then if the value of donated items is more than $5000, you will have additional documentation requirements including a requirement to have the goods appraised first.
Direct donations to individuals, no matter how needy, are never tax deductible.
