There are actually tons of great resources out there, but a lot of them are geared for older kids, not preschoolers. DK Books is always a great place to start for learning books, and I've included one of theirs here. Plus, I found a couple of other books with illustrations that look really appealing. I've heard great reviews of the discontinued Your Human Body book too, which you can find used on Amazon. Beleduc's puzzle is a great beginners choice, and the Janod puzzle will grow with your kids - just highlight more details as they get older. I have a feeling I'll be learning right alongside my kiddo.
- From Head to Toe: The Amazing Human Body and How It Works, $12.49
- The Little Brainwaves Investigate: Human Body, $11.04
- Under Your Skin: Your Amazing Body, $14.52
- 5 Layer Your Body Puzzle - girl or boy, $26, by Beleduc
- Body Magnet Puzzle, $30, by Janod
(Images as linked)