Power of attorney
You can find a valid form for granting power of attorney in New York State in the New York State General Obligations Laws, title 15 section 5-1513. (Or just go to the Consolidated Laws of New York State page and click General Obligations, and then title 15 or whichever one says”Power of Attorney”.) You also need to file a separate power of attorney for the IRS and one for New York State Department of Taxation and Finance. Some of these need to be witnessed by a notary public, but the signature of you (the principal) and the person you designate (the agent) need not be done at the same time.