I am looking for information that can help with the latest techniques / guidelines for the lay out and desing of PLC control panels in regards to the latest codes and standards. Any guidance as were to find this information is greatly appreciated.

 

In the USA refer to NFPA 79 "Electrical Standard for Industrial Machinery".

In Europe refer to EN 60204-1 "Safety of machinery-Electrical equipment of machines".

http://www.ab.com/manuals/gi/1770-in041a-en-p.pdf

 

What country are you in &c &c? You will need to be a bit more specific. Wire colours, fusing requirements, I/S considerations and so on depend on your target market (country / region / type of panel / location of panel).
If you are building a panel for a coal mine lift in Peru it would be quite different from a panel for a bottling plant cartoner in Andorra.

 

The panels will be primarily be installed in the US. Typical industries the systems will be implemented are Paper Mills, Automotive, Steel Mills, and various other manufacturing plants. Conveyors, assembly line and monorail crane systems are target areas.