One good source for "basic" CMM or layout theory is a Multi Metrics, Inc. book, written by Bill Tandler. If you can find one it gives a very decent explanation and representation of the hows and whys of setting up part coordinate systems, etc and can be a great help for someone just learning.
You can go to the web site for further information http://www.multimetrics.com/
Duane Wade
CMM/Gage Technician
TeleFlex Automotive - Pedals Division
301 W Ohio St.
Kendallville, In 46755
219-349-1985
dwade@tfxauto.com