1) Burt Dow, Deep Water Man by Robert McClosky (IMO the smartest childrens book ever written-)
2) Henry Builds a Cabin and others in the series (cute simpel storeis based on H.D.Thoreau.)
3) Miss Rumphius
4) Amos and Boris by william Steig (also Brave Irene)
5) The little red lighthouse and the great gray Bridge

Most Roald Dahl (all about 4th grade level, very funny books):
-George's marvelous Medicine
-The Twits
-The BFG
-James and the Giant Peach

-Catwings - about 2-3 grade level, very sweet, great for boys or girls and animal lovers

-Gooseberry Park- Cynthia Rylant

-Dinotopia- James Gurian - original beautiful picture books (with very challenging and interesting text)..

-Mrs. Frisby and the Rats of Nimh

happy reading