How does the Receiver of Memory's training proceed in The Giver?

Jonas initially experiences simple memories and then is gradually exposed to more difficult ones.

The initial training for Receiver of Memory is a little confusing for Jonas.  He had no idea what to expect, because no one in the community really knows about what the Receiver of Memory does.  Jonas is even told to keep his training secret, not discussing it with any other community members.

The Receiver of Memory’s work is so secret because he essentially knows all of the community’s secrets.  The community has no sense of history because citizens are prohibited from having books and as far as they know things are as they always have been.  The community tightly controls all information in an effort to maintain Sameness.  Only the Receiver of Memory even has books.

The training begins with the old man, who tells Jonas to call him The Giver, sharing with Jonas some concepts that he has never previously experienced.  He shares with him the idea of snow, a sled on a hill, and sunshine.  None of these things exist in Jonas’s community under the control of Sameness.

Memories are shared through some kind of special sense the two share.  The Giver just puts his hands on Jonas's back and he can see what the old man remembers.  This is called the Capacity to See Beyond.

As Jonas proceeds, he learns what the Capacity to See Beyond means.  For one thing, it means that he can see things that others can’t.  He can see the memories, yes, but in his everyday life he can also see colors.  No one else in the community can see colors.

"Of course. When you receive the memories. You have the capacity to see beyond. You'll gain wisdom, then, along with colors. And lots more."

Jonas wasn't interested, just then, in wisdom. It was the colors that fascinated him. "Why can't everyone see them? Why did colors disappear?" (Ch. 12) 

The Giver explains to Jonas that people long ago gave up color in order to pursue Sameness.  Sameness mattered more to them than seeing color, and seeing colors stood in the way of Sameness.  Jonas realizes this when he comments that color offers people choices, and it would be nice to be able to make choices, but dangerous. 

As Jonas’s training proceeds, he learns more and more things about the past.  The Giver begins to transmit pain, first in small minor ways and soon in profound ones.  He starts with a sunburn and later shows Jonas war, poverty, and death.

Going closer, he watched them hack the tusks from a motionless elephant on the ground and haul them away, spattered with blood. He felt himself overwhelmed with a new perception of the color he knew as red. (Ch. 13)

Seeing an elephant die must have made quite an impression on Jonas.  In Jonas’s community, there is no death.  There are also no elephants.  Jonas’s community does kill citizens with impunity, from infants to the elderly, but no one understands this as death because it is all kept secret. 

The pain that the trainee receives is not easy to process for such sheltered young people.  They are only twelve years old when it starts.  Jonas's predecessor, a girl named Rosemary, chose to apply for release because she did not want to live with the pain and knowledge she acquired.

Jonas has the ability to ask any question of anyone and see anything that he wishes.  This is easy, because everything in the community is recorded.  He watches a recording of the release of a newborn infant, conducted by his father.  This video, and the realization that release means death, changes Jonas’s perception of the community forever.  He had previously longed for concepts such as love and family to return to the community, but at this point he realized just how far gone his community was.