Prophet (SAW)'s Prayers When burying the dead

Recite:

بِسْمِ اللَّهِ وَبِاللَّهِ وَعَلَى مِلَّةِ رَسُولِ اللَّهِ

"In the name of Allah and with His aid and on the Madhab (deen) of the Rasul of Allah I place him in the grave". (Hisnul Hasin)

After the burial recite Surah Fatiha and the beginning of Surah Baqarah at the head side and the last ayats of Surah Baqarah at the feet. (Mishkat)

Stay a little while at the grave side and ask Allah for forgiveness for the dead and make dua that he remains firm at the time of questioning by the angels. (Hisnul Hasin from Abu Dawood etc)