Often full of nonsense (e.g. "A green dog on a yellow tree.") the story is full of language fit for beginning readers and opportunities for parents to use the text as a learning tool (asking for shapes and colors or the location of the preposition depending on the child's age).
Interspersed in the story, there is an ongoing silly conversation where one dog asks the other, "Do you like my hat?" This was always my favorite part as a child because the hats get more and more elaborate as the dog tries to find one that will really impress the other. Your children are sure to laugh, and in reading this book with children, I've found that this silly exchange gives children the break they need from concentrating on the opposites, etc. and keeps them interesting in pressing forward in their reading.
The only negative element that Go, Dog. Go! contains is a matter of grammar. There are several places where there are periods following phrases. (E.g. "Three dogs at a party on a boat at night." This is not a sentence because it does not contain a subject-verb combination.) While this is often an acceptable technique in fiction-writing, I am surprised that P.D. Eastman used this in a children's book, especially a beginning reader. Parents may wish to use this as an opportunity to teach their children about what grammatical elements make a sentence and have their children identify every misplaced period.
There is also a character from one of P.D. Eastman's other popular works hidden within the illustrations of Go, Dog. Go!. Can you find it?