There are three basic reasons for a Headstone:
- To mark the place as “tameh” (spiritually impure and off-limits for kohanim).
- To mark the place for people who want to visit it.
- To honor the deceased.
According to the renowned book called "Gesher HaChaim" – The Bridge of Life - when visiting the grave during the first year it is customary to say seven paragraphs of Psalms: 33, 16, 17, 72, 91, 104, and 130. Afterwards one says Psalm 119 and recites the verses that spell the name of the deceased and the letters of the word "Neshama" -Soul. Different communities have different customs so you should check with the Rabbi of your community if possible (that’s a great source!).
There are a number of excellent English books available regarding the laws of mourning. For example: "Gesher HaChaim – The Bridge of Life" by Rabbi Tukachinski; "Mourning in Halacha" which is published by ArtScroll; "The Jewish Way in Death and Mourning" by Rabbi Maurice Lamm; and “The Funeral and Cemetery Handbook” by Rabbi David Weinberger and Rabbi Jacob J. Schacter, ArtScroll Publishers.
I conclude with the traditional blessing and pray that: "May God swallow up death forever; may He wipe away tears from every face. (Isaiah 25:8)