A free template for an intent-to-vacate notice for tenants to give landlords can be found at Rent.com. The letter should indicate the date that it was written as well as the specific date on which you intend to vacating the premises.
The intent-to-vacate letter should also include your phone number and mailing address as well as information about any security deposit.
ApartmentGuide.com also offers a free template for intent-to-vacate letters. The website recommends reading over your lease to confirm details of your move-out arrangement, so the wording of your intent-to-vacate letter is consistent with the language and requirements of the lease.