Great bookstore for kids!
As a prior teacher and mother I love books, as do my children! A great way to entice them is to take them to the library first to get their Library Card (make sure you look online as to what identification you need to bring fyi :).)
In the trips to various book stores, a great one that I love is Scholastic Store in NYC. Located at 557 Broadway between Prince & Spring Streets (212) 343-6166, open daily at 11am. They feature a plethora of books, learning materials, and much more!
I say make a half day out of it! Get there when it opens, then walk around Soho and enjoy the shops, and the great restaurants/cafe’s for a quick-lunch. Go to Zagat.com for restaurants in the area.