I am a CNC Supervisor in a machine shop with about 30 machines and 90 Machinists/Operators. We have a variety of CNC mills (VMC, HMC, pallet changers, etc) and lathes (live tooling, twin turret, etc.), and am looking for recommendations for books that my guys can check out to help with their understanding of machining, programming, inserts, etc., as well as lean and other business practices. I would rather have several smaller books than one huge books. Our guys have a pretty wide skill range from button pushers to experts. One book I already plan to obtain is Machinery's Handbook. Recommendations? Thanks!