A Pop-Up Book of Nursery Rhymes Matthew Reinhart Little Simon, $27, 10 pages; ages 3 to 6 Generally, I hesitate to recommend pop-up books for toddlers. Their technical paper structures are like magnets to little fingers. But Matthew Reinhart's "Pop-Up Book of Nursery Rhymes" is an exception. It's irresistible. While adults will marvel at the engineering and Reinhart's frisky pet mouse, youngsters will "ooh" and "ahh" at the colorful moving parts and hear rhymes destined to become part of their lives. The first peek at Humpty Dumpty shows he's all smiles atop a red brick wall until the book opens wide and he starts to fall.