1) Get a copy of Machinery's Handbook
2) Read Machinery's Handbook
3) Refer to Machinery's Handbook often
4) Don't be cheap and then complain about it
5) Learn manual milling before CNC
6) DON'T keep doing the same things over and over and expect different results
7) If any way possible, be in face to face contact with other machinist and learn from them
That is all I got for now.