Limor Fried (aka Lady Ada) not only produces and sells a lot of really interesting electronics hobby kits, she also offers a vast collection of educational resources including Adafruit Academy and the Adafruit Learning System,. The latest addition is is the "E is for Electronics" colouring book.
Designed to foster a love for electronics in kids, the colouring book has one page for each letter. The word to be learned for each letter typically teaches a common electronics component along with the inventor. You can purchase the 26-page book for $US9.95 or download a PDF for free.
Lady Ada's "E is for Electronics" [Adafruit Industries]