First book was around 4 years of age; I can't remember the title, but the main plot was that a kid's dog felt ignored, something or other about paying attention to an egg that was hatching. The dog, with some help from squirrels and rabbits, etc., made an egg for the dog to be inside out of sticks and stuff. It was painted really colorfully. They rolled the egg to the center of town. Everyone was excited except the boy - he was sad because his dog was missing. Then, the dog hearing this broke out of the egg and everyone was happy. The end.
I can picture some of the pages in my head, but cannot remember the name of the book. My parents got me a big box/collection of similar length books when I was in kindergarten. I read them all multiple times, but that one was one of my favorites.