For those who need transliteration, the Amavasya Tharpanam Guide from Vadhyar.com covers basic mantras like Achamanam and Sankalpam.
Yajurveda Amavasya Tharpanam is a ritual performed on the new moon day (Amavasya) according to the Yajurveda tradition. Tharpanam is a ritual where water is offered to the ancestors and the gods, seeking their blessings and forgiveness. Yajurveda Amavasya Tharpanam In Sanskrit Pdf