Please be aware that for the purpose of this document, the term "Mezuzah" refers to the scroll which Jewish law mandates be placed on certain doorposts. The plural of "Mezuzah" is "Mezuzot."
Because a Mezuzah has intrinsic holiness, items which function with it are considered items which serve holiness, and they may not be disposed of. Instead, they are buried: Megillah 26b
Putting a Mezuzah scroll down, text-side down: Eruvin 98a
Whether the parchments must be connected with sewn animal veins: Megillah 8b
Writing the Commandments [of Writing a Mezuzah and Wearing Phylacteries] in the Doorpost Scroll, as well as the core of those Sections of the Torah: Berachot 15b