In General Military manuals are a great resource, one which people, even people in the military, don't generally appreciate. But as they are not great literature and they were not intended to be, they are working instructions and notes. They are loaded with a vast amount of information, accumulated with great difficultly, often at the cost of many peoples lives. A lot of effort, a vast amount of experience, time and thinking, not to mention money, went into making them. New military manuals are useful explanations of what is the current doctrine.
Old manuals are sources of historical doctrine, procedures and techniques.
They are often repositories of lost knowledge which can be reapplied, often saving people from having to 'reinvent the wheel'. Manuals in general are useful for many different types of people when properly read and used. Lost Knowledge Military manuals have short working life spans. Field manuals are usually replaced every ten years. Technical manuals are in print as long as the army has the piece of equipment in inventory.