The Bare Naked Book by Kathy Stinson with art by Heather Collins, paperback non-fiction, first published in 1986, this edition published in 2006 by Annick Press.
This is a simple look at our bodies, and the different parts that make them up. With basic language and clear illustrations, this is a nice book for toddlers and preschoolers. It introduces each part of the body, with some illustrated examples of each, such as pushing arms, hairy nipples and stamping feet. At the end of each page, it asks the child to locate that body part on themselves, which is a great prompt for learning body parts and for body awareness.
My preschooler liked the pictures, and had fun locating all her body parts as suggested by the book. She enjoyed perusing this book on her own too, looking at the pictures, and pointing out what the different parts of the body were doing.