A mezuzah scroll (Hebrew for doorpost) is a piece of parchment (often contained in a decorative case) inscribed with specified Hebrew verses from the Torah (Devarim (Deu)6:4-9 and 11:13-21), a passage commonly known as the Shema . It intents to comply with “on the knobposts of your house” (Devarim (Deu) 6:9). The mezuzah is not, a good-luck charm, nor does it have any connection with the lamb’s blood placed on the doorposts in Egypt. It is a constant reminder of YHWH presence and YHWH mitzvot. The parchment is prepared by a qualified scribe, and the verses are written in black indelible ink with a special quill pen. The parchment is then rolled up and placed inside the case.
The mezuzah case with the scroll should be placed on the right side of the door or doorpost, approximately at shoulder height and in every room of the house except for bathrooms. The owners should take take care of the parchment or the wording on it, since it is considered Torah. Mezuzah cases are produced from a wide variety of materials.
Where to Affix a Mezuzah:
The mezuzah is placed the right doorpost as one enters the room, at shoulder height, in a slightly slanted position so that the top points toward the inside of the room.
Blessing on Affixing a Mezuzah (ceremony called Chanukkat Ha-Bayit):
Barukh atah Adonai Eloheinu melekh haolam, asher kideshanu bemitzvotav vetzivanu likboa mezuzah.
Blessed are You, Lord our God, King of the Universe, Who sanctified us with His mitzvot, and commanded us to affix a mezuzah.
It is proper to remove a mezuzah when you move. The mezuzah is also a symbol of YHWH watchful care over the home. The name of Sha-dai, which appears on the reverse side of the parchment, is an acronym for the Hebrew words which mean “Guardian of the doorways of Israel.”
See How to Affix a Mezuzah scroll:(from youtube.com, JewishPathways.com)