I just wanted to add a couple of books I have discovered:

Michael Reisman's "Simon Bloom, The Gravity Keeper" and "Simon Bloom, The Octopus Effect" are really terrific Junior Fiction SF books. Highly recommended for the scientific-minded! Science as magic, three 11-yr-old kids take on some evil grownups with really awesome physics and biology powers gained from the "Teacher's Editions" of physics and biology (one in each book) and save the world.