My Bus, by Byron Barton is a fun little book that's sure to become a read aloud favorite.
Joe drives a bus. He picks up and drops off a variety of brightly-colored chunky-sized cats and dogs all over town. As the animals board the bus the count is predictable....one dog gets on at stop number one, two cats get on at stop number two, etc, until the bus is full of cats and dogs. When the animals get off the bus, however, they do so in random groupings -(two cats and one dog, one cat and two dogs, etc.), and with varying purposes and destinations, (some board a boat, others take a plane...) and so it goes until only one dog is left on the bus with Joe. This is Joe's own dog, as it turns out, and the two leave the bus at the station and head for home in Joe's little car.
More than a good little story, this book introduces the concepts of ordinal and cardinal numbers as well as different forms of transportation, a variety of verbs to convey different kinds of action, and simple counting from one to ten. It's perfect for toddlers and a good choice for preschoolers or even beginning readers.