Some books on electrical wiring might be a good idea. Maybe someone can suggest some reading material on rigging. Not so that we'd all become electrical wiring or rigging experts, but so that we would be able to recognize safe vs. unsafe practices. (And so those who absolutely insist on doing it themselves might at least get close to doing it right.)
I haven't read this book, but others have recommended it:
Electricity for the Entertainment Electrician by Richard Cadena
I have an old version of this book. Covers general-purpose electrical wiring. Easy to read and understand; written for the North American market and based on the National Electrical Code:
Practical Electrical Wiring by Richter & Hartwell
And a "Reader's Digest condensed" version of the above:
Wiring Simplified, by Richter, Schwan, & Hartwell
Lastly, consider that since the National Electrical Code is revised every three years, electrical wiring methods and materials can and do change over time. Old versions of electrical books should be avoided because they may present methods and materials that are no longer acceptable.