At the one we went to they did three things:

Pass The Puppy; where you pass the pups round a circle of people and each person looks at their teeth, in their ears and feels all their paws and then passes the pup to the next person. It gets them used to being handled by different people.

Meet And Greet; all the owners take it in turns to walk around the circle and meet each puppy in as calm a fashion as possible, this is to teach them how to behave around other dogs when on the lead.

Playtime; a free for all where the puppies play amongst themselves, all the owners have to ignore the dogs if they come up to them, this is to build confidence and encourage some independance. It also gives a good opportunity for owners to ask attending veterinary nurses and staff about any problems or queries.

Our two pups only went three times before they "graduated", due to them being so dominant and confident.