The best book I have come across for building panels is on
Power Quality Equipment - REO (UK) Ltd
Explains all about layout,earthing and cable shielding written by cherry consulting a well known rfi consultant
They also have some fantastic info on harmonics which you need to understand if you are going to install vsds
The panel building standard is bsen60204
Most of which is a cut and paste of 17th edition ......
Good question to start what colour do you want the start button to be ? That's not a joke
Safety for simple stuff has to be done under bsen13849 I recommend using sistema for the calcs and the documentation
Sistema is free
For safety equipment my favourite is pilz the main reason is if you ask them a question they will give you an answer and an application example
Start with the customers risk assessment and work backwards
If no risk assessment assume PLe