The basis of this is to grow the puppies brain by exposing him to specific stimulus in order to ilicit specific neurological responses. This means the puppy is happy, confident, and curious.

Pffafenberger sited 4 critical periods of development.

Day 1-19, baby puppies need warmth, food, massage, sleep
Day 20-49, infant puppies learn to play, learn limits, and learn dominance
Day 50-84 (7-12 weeks) puppies learn independence and relationships with people and other animals, and they learn fear
Week 12-16, puppies learn self-confidence, housebreaking, that they must obey and the difference between play and work
The senses (which work very well into the Rule of 7 as well)

Smell - the breeder's hair, cinniman, fresh peppers, horseradish, vanilla extract, liver brownies, another dog's bedding, carrots, bird feathers
Touch - sheep's wool, towels, denim, carpet, linoleum, concrete, cold metal pans, newspapers, magazines, indoor-outdoor welcome mat, vinyl, pan of dirt, screen for storm door (do this from Day3+)
Hearing - movies, radio, talking on phone, other dogs howling, speaker phone, dropping keys and kitchen utensils, bell, cap gun, vacuum, wind-up clock, stomping on floor, slamming doors
Vibration - Vacuum cleaner, back massager, hair dryer, can opener, mixer
Sight - people, animals, TV, cars, machines, shrubs, large toys, books, EVERYTHING
Taste - Beginning Week3, everything

The book can be found at http://www.dogwise.com/