The concept of these books is so simple yet effective. Each page has a different person/object (depending on the title of the book), which for some reason "is not my..." because it is too furry, rough, smooth, shiny, etc etc. Different textured materials are used throughout and make the books very nice to touch. The illustrations are very simple and effective. Our baby likes looking at them (from 2 months up) and as she gets older I'm sure she'll really appreciate them.
There are so many to choose from... I want the whole set! (and they're cheap too!).