Sci Fi 101 (Score 1)

The Heinlein Juvi's (Have Spacesuit Will Travel, The Star Beast, The Rolling Stones, etc) and... ah heck, all Heinlein is OK for kids.

Pournelle's "High Justice"

Pournelle and Niven's "The Mote in God's Eye" + "Ringworld"

H Beam Piper's "Little Fuzzy"

Andre Norton's Witchworld series

L 'Engle's "A Wrinkle in Time"

L Neil Smith's "The Probablility Broach"