The inspiration for this site http://www.micro-machine-shop.com/ Dr. Pinkus is quite a bit more skilled than I and the way he detailed his equipment was very appealing to me.
The Home Shop Machinist https://secure.villagepress.com/
Machinist’s Workshop https://secure.villagepress.com/
Digital Machinist https://secure.villagepress.com/
Model Engineers’ Workshop http://www.model-engineer.co.uk/editorial/page.asp?p=250
“Machine Tool Practices” by
“Machine Shop Practice” Volumes 1&2 by Karl Moltrecht. Many copies available used. Covers the very basic detail needed to machine for the first time. Milling is covered in Vol 1 and Turning in Vol 2. I found vol 2 to have more useful information for current hobby use (technology has changed less). I reread sections of these book regularly. Written as instruction for Industrial training.
Workshop Practice Series. Many books, each with a specific subject. Take your pick. Written as much as three decades ago in the UK so some terminology may be out of date or different than US customary but not too tough to work out. These books cover a specific topic through completion of project(s). Most detail about how to do one specific process. Written for hobbyists.
“Fundamentals of Dimensional Metrology (Mechanical Technology Series)” by Ted Busch. Very good text on measuring and measuring tools. Covers everything from the invention of measuring systems to calibrating a dial indicator and more. This is actually a text book but I read it most of the way straight through with great interest. (This may classify me as a nerd). Has very good detail on proper selection, use and calibration of precision measuring instruments. College or technical school text book.
“CNC Programming Handbook, Third Edition” by Peter Smid. The only single source I have found yet that has all of the G and M codes with explanation and discussion of when to use which function.
“Metalworking: Doing It Better” by Tom Lipton. Basically the same book as “Metalworking: Sink or Swim” but layed out better (pictures are closer to the test they refer to). A compilation of tips. This is more useful once you have some experience.