Regarding the mastery of arms, if you are going to carry a firearm every day it behooves you to educate yourself. One of the most convenient aspects of these two manuals is that they are truly handbooks. They are compact enough to carry in your briefcase or duty bag.
Broken down into short chapters it is easy to read one section at a time during breaks or those slow hours late at night when you may be struggling to stay awake. The material is available. The next step is yours.