We couldn't find any policy on the development of Task books in the DoD or DoN, but we found a definition of Task Books. 

What is a task book?

Task Books allow you to enter tasks and procedures for common reactive and routine maintenance so you can easily add them to work orders or schedules.

Navy reference OPNAV INSTRUCTION 1500.76D to "one books" or "handbooks"

The "DOD Dictionary of Military and Associated Terms" does not have the term "task book" listed in their 270 pages of terms.

Based on our research, a "task book" sounds like a local product for the Navy.

Recommend that you reach out to your cognizant higher headquarters for more information and policy requirements for the use of Task Books.