Here it is in short form.
Prior to affixing a mezuzah upon a doorpost which has a door, the following blessing should be recited:
Baruch Ato A-do-nai Elo-heinu Melech Hoolom asher kideshonu b"™mitzvotov v"™tzivonu likboa mezuza.
Translation: Blessed are You, L-rd our G-d, King of the universe, who has sanctified us with His commandments and commanded us to affix a mezuzah.
The blessing "śShehecheyanu"ť is not recited.