Nonfiction book, easy read, big ideas, great for boys??
(and girls!)

My DS loved loved loved this one:

'Now and Ben
The Modern Inventions of Benjamin Franklin'

A colorful picture book of the various inventions which Benjamin Franklin came up with or improved on. Brief but insightful discussion of why his inventions have been so long-staying in usefulness. This was perfect for our ds, as he is a bit of a global thinker/inventor type himself. It shows the side of Benjamin Franklin you don't often see in the history books: a playful boy, a lover of books and of course, wicked smart! smile
Illustrations are detailed, with lots of little 'oh, look!' moments.

http://www.amazon.com/Now-Ben-Inventions-Benjamin-Franklin/dp/0805079173