This set is sometimes referred to as "Peanuts Preview" but this really only applied to the promo card, which is entitled "A Celebration Preview Prototype".
This card has a bit of a surprise, as it is one of the few places where you will find out that the "M" in Charles M. Schultz stands for "Monroe".
The rest of the set consists of cards of the major characters, these being Charlie Brown, Franklin, Linus, Lucy, Marcie, Peppermint Patty, Pigpen, Sally Brown, Schroeder, Snoopy, Spike, and Woodstock. Lucy actually appears again, in her psychiatric booth, rather than allot the space to another character. And so does Linus, waiting for the Great Pumpkin.
Then there are cards of Snoopy and his activities, most of which he does but in his dreams - basketball, camping, enjoying Easter, fighting the Red Baron, golf, ice hockey, in space, kissing Lucy, posing in his sunglasses as "Joe Cool", pretending to be a vulture, tennis, winning Gold at the Olympic Games, and writing the Great American Novel.
The final cards deal with a facet of the Peanuts world that Mr. Schultz probably never imagined, its moving from a flat cartoon to stage and screen and into popular culture. So card 26 speaks of "You`re a Good Man, Charlie Brown", a stage musical which opened off Broadway and traversed the world - as well as being successfully screened on television. Card 27 reminds us that a book, called "Happiness is a Warm Puppy" (which is totally true in my world) was the first ever cartoon character book to make the New York Times best seller list. Card 31 shows the first ever Peanuts feature film, "A Boy Named Charlie Brown". Card 32 tells of the 1973 Thanksgiving Special, which won an Emmy. And Card 33 features their first ever Christmas Special TV programme.
There is a rather magical, kind of parallel, set associated with this, as Mr. Schultz signed every card in one of the sets, and it was then scattered to the winds amongst the distribution chain, with true pot luck as to where it fell.