The Birthday Present, by Mavis Smith is a perfect short story for a preschool classroom library where the children can follow the easy picutres in free reading time. It is about a young dog that goes to get his mother a birthday present (a topic that preschoolers find interesting).
This is a fun wordless book (or mostly wordless, anyway) that allows the parent and child to narrate the book together. The pictures are colorful and tell the tale well, and there are interesting details to point out along the way.