Sylvan Dell Publishing does a fantastic job of promoting their books in unique and meaningful ways. Have a look at this week's blog post about kids in the kitchen and how you can use cooking to teach science and math skills.
In addition they offer e-books in English and Spanish, all their books have For Creative Minds sections in the back that extend the topic of each book in fun and engaging ways, all the books are curriculum aligned, are Accelerated Reader, and offer tons of teaching activities online. They are truly unique - delicious, wholesome, healthy brain food. Plus recipes!