George's Secret Key to the Universe
George's Cosmic Treasure Hunt
both by Stephen Hawking and Lucy Hawking.

http://www.amazon.com/Georges-Secre...mp;s=books&qid=1247795812&sr=8-2

My DS8 who loves math and science really enjoyed them. They are full of science concepts with interesting stories.

Hank the Cowdog series by John R. Erickson
Very funny series.

Hank Zippzer series by Henry Winkler andLin Oliver.

http://www.amazon.com/Niagara-Falls...mp;s=books&qid=1247797142&sr=1-1

My 2E son loves Hank, who has learning disabilities.

Pick Me Up
http://www.amazon.com/Pick-Me-Up-Jeremy-Leslie/dp/0756621593/ref=ed_oe_h

Very interesting non-fiction with full of information about many subjects.