What sort of vehicle Sheri? Heavy, or Ute/Car Trailer loads, are you looking for attendees to achieve Unit Standard 1753 (Load and unload a general freight vehicle).
This is an interesting topic and one that I get questions about from some colleagues. (In relation to truck and trailer units)- Ultimately load security is the drivers responsibility however we are finding that more and more companies require our drivers to stay inside their cabs or in a 'box' while the truck is loaded by the client. Sometimes our drivers have very minimal involvement. I would love to hear what others think about this as its tricky. The clients are only trying to protect themselves/manage their risk as low as possible on their site but this can have consequences down the line once we try to unload the truck on our own site.
When looking at the chain of responsibility, yes it is the drivers but there is also shared responsibility for load restraint, some years ago I would not allow a vehicle to leave our premises until he restrained the load correctly. I am unaware of any formal courses but maybe contact the road transport association.