What Do Wheels Do All Day? by April Jones Prince, illustrated by Giles Laroche. 
This is a great nonfiction book for children, covering the many ways that we use wheels in our lives.  The text is very brief and has an unintrusive rhyme pattern that keeps the book moving along.  It is the illustrations that make this book so special.  Laroche uses paper relief art to create illustrations with depth and motion.  This book will start up conversations with children about what other types of wheels they can think of and how they are used.  And what could be better than a nonfiction book that gets kids thinking all on their own?  This book is great for school units but will also be picked up by children interested in vehicles of all types.  The text and pictures are more than appealing enough for this to also be added to any vehicle storytime.