Each book in the set contains 8 pages of actual words for the child to read with an additional last page that always says "The End." Most pages have 4 to 6 words on them. In this set, book 6 is the challenging book because one page has four sentences and 15 words. Book 6 of the set also has several pages with double lines. We started reading these a couple months before my son's fourth birthday because he had finished all his letter sounds in a Montessori pre-school that year. A friend said her four year old was reading with these books so I said why not. When I we did the first book, I can't say my son was reading them himself right away. I had to help him learn the word in each book one time and then he was doing it himself. By book four he was sounding out words himself. The first time you read a new book in the set it is painful. I make my son master the book he is on before he can go onto the next one. The one exception in this set was book 6, its particularly painful, I think due to that one page with two sets of lines. I am now getting Stage 1 Stories to supplement. My son is beyond excited when he finished a book and has to call grandma to tell her when he has moved on to the next book in the set. It's awesome to see how proud he is of himself. I used to read 4 to 5 books a night to him and now I am lucky if I get in one or two. He is reading the others.