I don't know about tutorials and if so, I wouldn't recommend it.
Either you know exactly what you are doing or you should contact (physically, not via a virtual advice) somebody who knows how to deal with the combination.
In general: The setup has to be such that by no means the user can get in touch with mains power.
By no means = one should always assume that a user will always do something which you would never do and you have to take precautions for such a foolish user behaviour.