Imperial Munitorum Manual
The Imperial Munitorum Manual is a background book written by Graham McNeill and published by Black Library, in the style of the basic instruction manual published by the Departmento Munitorum for Imperial Guardsmen. It includes sections about the organization of the Departmento Munitorum and Imperial Guard Regiments, and several sections regarding equipment and its procurement and maintenance. It seems that each major recruiting world gets its own edition, presumably to reflect the local regiments' organization and operating procedures. The Munitorum Manual actually published by Black Library is the "Cadian edition".
In many ways, it can be compared to the Imperial Infantryman's Uplifting Primer, in that it includes some useful information for a Guardsman mixed in with a comically rose-tinted depiction of the Imperium, though the Munitorum Manual seems a little more frank about the grimdark parts. For example, it plainly declares that the life of a Guardsman is worth less than the equipment he carries (especially for ill-understood technologies, like plasma weapons), and that the average Guardsman dies within six months of his recruitment. It also includes sample requisition forms, the fine print for which includes the paragraph:
For the purpose of any event of dispute between the Departmento Munitorum and requisitioning soldiers, the Departmento Munitorum may treat the particular event that actually happened as not having happened and/or treat any particular event that did not actually happen as having happened.