We just found a very nice guide published by Slaughter, a manufacturer of testing equipment.

This Guide to Electrical Safety Testing is free to access on the internet.

Here is what it explains:

• What is class I and what is class II
• The two lines fo defense to protect the user from electrical shock (insulation, and safety grounds)
• What tests are to be performed on samples, and what tests are to be done on 100% of products
• Types of injuries that can be induced by electrical shocks
• How to set up a safe workstation (with nice graphics)
• Checklist for setting up a safe test station
• Clear explanation of the hipot test
• Clear explanation of the ground continuity and the ground bond tests (and which one to apply)
• Clear explanation of the insulation resistance test
• Chart with settings for most common tests and standards

If you work with electrical products, especially for sale in the US, I strongly suggest you get that document!