Fiction: 
       Here's a list of great fiction books recommended to stimulate your kids' 
imagination and interest in the solar system:

Elementary school Fiction:

Daniel Pinkwater series (here are some titles, there are too many to put all of them): 
He's a funny and inventive writer with a little odd stories. They are imaginative 
and will get your kids to have bigger imaginations. 
    Fat Men in Space by Daniel Pinkwater
    This funny adventure book, will have your kids squealing! It's very imaginative 
    and soon they'll be wanting radio teeth. It also encourages eating healthy foods 
    because all the fat men from space have eaten it all!
    Ned Feldman, Space Pirate
    Mush, a Dog from Space
    Guys from Space
    Spaceburger
    Alan Mendelshon, the Boy from Mars

The Fallen Spaceman by Lee Harding

Magic School Bus Goes to Space by Joanne Cole
An informative and yet somewhat adventurous book, on the journeys of Mrs. Frizzle's 
class through the solar system.

Middle school Fiction:

Douglas Adams Series
A very fun and exciting series, starting from the Earth being blown-up, to custom 
ordered planet to mice doing experiments on people and dolphins being extraterrestrials, 
and before the earth is they give everyone a perfectly crafted glass bowl that says 
"So long, thanks for the fish." 
   Hitchhiker's Guide to the Galaxy by Douglas Adams
   So Long, and Thanks for All the Fish
   The Restaurant at the End of the Universe

Bruce Coville Series My Teacher is an Alien by Bruce Coville.
Another great series of books, it will stimulate any reader's imagination and think 
twice about TV (TV was planted on Earth to slow the pace of humans getting far into 
space by melting the kids' brains) and about how humans would match up in a moral 
hygiene test.
   My Teacher Fried my Brains
   My Teacher Glows in the Dark
   My Teacher Flunked the Planet

High School Fiction:

2001: A Space Odyssey by Arthur C. Clarke
A classic science fiction book, one of the firsts, still has a great plot. This book 
was also made into a movie, another classic.

The Right Stuff by Tom Wolfe
The "right stuff" are the qualities that make a man the best, and for astronauts 
they had to have all the "right stuff". Competition between countries in the race 
for space, between the people, between airplane pilots and between the astronauts 
compete throughout this book.

The Martian Chronicles by Ray Bradbury

Non-Fiction:

      Fiction is not true, so there is the non-fiction section and reference section. 
Here are some great non-fiction books on the planets and the cosmos:

Elementary School non-fiction:

The Search for Planet X, written by Margaret K. Wetterer. 
Contributors to this book include Dr. Henry Giclas of the Lowell Observatory who 
still works there and who knew both Clyde and his sister well. The book is published 
by Carol Rhoda Books, Inc., Minneapolis, 1996, 48 pages. It is written for 3rd and 
4th graders and includes sketches of Clyde's cat "Pluto" who was was with him since 
1990.

solar system series by Seymour Simon. 
1st and 2nd grade. Lots of big pictures. 
published by Morrow Junior Books, New York. 
   Mercury
   Venus
   etc...

Isaac Assimov's New Library of the Universe. Pretty high level topics for elementary school,
but the writer, Isaac Assimov is one of the smartest people in the world, so what 
do you expect? For 3rd and 4th graders. Published by Gareth Stevens Publishing. 
   Nearest the Sun: The Planet Mercury
   The Ringed Planet: Saturn
   Planet of extremes : Jupiter
   A distant puzzle : the planet Uranus
   The red planet : Mars
   The sun and its secrets
   Our planetary system
   etc...

Middle School non-fiction:

Planets X and Pluto by William Graves Hoyt
for other points of view regarding the search for the ninth planet. published by The 
University of Arizona Press, 1981

The Planets by McNab, David, and James Younger. 
Full of pictures about the planets from the Hubble space telescope and very pretty, 
but information is pretty general and not at a high level. This book is meant to be 
read from front to back, not suited for reference. Published by New Haven and 
London: Yale University Press, 1999. 

High School non-fiction:

The Universe. Text book. Editors: Kaufmann and Freedman. 
This text books is very elaborate and tells you everything you need to know about 
looking at the stars and cosmos. Also teaches some of the physics involved with the 
Universe. Also includes a CD-ROM with "Starry Night." Published by the W.H. Freeman 
and Company, New York. 

The New Solar System. by Faith Vilas and Ed. J. Kelly Beatty, Carolyn Collins 
Peterson, Andrew Chaikin. 
This book is like a text-book but doesn't include activities and physics of the 
universe. Has a lot of information on the planets and their satellites. published 
by Cambridge University Press: Cambridge, Massachussets, 1999. 

Jupiter-the Giant Planet byReta Beebe 
This is a very in depth book all about Jupiter. Published by: Smithsonian Institute, 
Washington D.C. 1997.

Venus Revealed  by David Harry Grinspoon. 
Also a very in depth book just about Venus. Published by: Addison-Wesley Publishing 
Company, Inc.New York; Reading, Massachusetts; Menlo Park, California; Don Mills, 
Ontario; Harlow, England, 1997.