As exemplified by the previous recommendations, gun bibles come in two varieties: General purpose and model specific. Both types are obsolete as soon as they are published. New models and cutting edge accessories won't be shown in either variety. However, tasks like stock fitting and finishing are virtually timeless. The model specific books are probably much more detailed than needed for your purposes. With the internet, you have access to up to date information on countless subjects.
For your library, I recommend one, or more, of the general purpose bibles. If you want an up-to-date answer to a specific question, then do an internet search: "How to mount a scope on a ____________" Also, with the internet you have more than one opinion on any given subject. It's always nice to have a consensus before you do something significant to your favorite arm.