- The Frog and Toad Treasuryby Arnold Lobel 
- Tillie Lays An Eggby Terry Golson 
- The Real Holeby Beverly Cleary 
- Rikki-Tikki-Taviby Rudyard Kipling, illustrated by Jerry Pinkney (abridged) 
- Are You a Grasshopper? (Backyard Books)by Judy Allen 
- The Biggest Dinosaursby Michael Berenstain 
- Big Chickensby Leslie Helakoski 
- Are You a Dragonfly? (Backyard Books)by Judy Allen 
- Big Chickens Fly the Coopby Leslie Helakoski 
- Are You a Butterfly? (Backyard Books)by Judy Allen 
- Today Is Mondayby Eric Carle 
- Fox In Socksby Dr. Seuss 
- Becoming Butterfliesby Anne Rockwell 
- A Day in the Life of Murphy (Bccb Blue Ribbon Picture Book Awards (Awards))by Alice Provensen 
- Roar!: A Noisy Counting Bookby Pamela Duncan Edwards 
- Dora in the Deep Sea (Dora the Explorer Ready-to-Read)by Christine Ricci (ugh) 
- Minnie and Moo: The Case of the Missing Jelly Donut (I Can Read Book 3)by Denys Cazet 
- Are You a Ladybug? (Backyard Books)by Judy Allen 
- Are You a Bee? (Backyard Books)by Judy Allen 
- AlphaOops!: The Day Z Went Firstby Alethea Kontis 
- Into The A, B, Sea: An Ocean Alphabet Bookby Deborah Lee Rose 
- Do Not Open This Bookby Michaela Muntean 
- Chickens Aren't the Only Ones (World of Nature Series)by Ruth Heller 
- Storm is Coming!by Heather Tekavec 
- Little Fox Goes to the End of the Worldby Ann Tompert 
- It Could Always Be Worse: A Yiddish Folk Tale (Michael Di Capua books)by Margot Zemach 
- Eric Carle's Animals Animals(selected poems) 
- Egg Dropby Mini Grey 
- Katy and The Big Snowby Virginia Lee Burton 
- Boo and Baa at Seaby Olof Landstrom and Lena Landstrom 
- Olive, the Other Reindeerby Vivian Walsh 
- Dinosaur Dreamby Dennis Nolan 
- Dinosaurs Before Dark (Magic Tree House, No. 1) by Mary Pope Osborne *
-  The Knight at Dawn (Magic Tree House, No. 2)by Mary Pope Osborne * 
- Mouse Soupby Arnold Lobel 
- Mummies in the Morning (Magic Tree House, No. 3)by Mary Pope Osborne * 
After much searching on the web, I found some leveled reading lists that gave me a place to start. I searched for books that were a bit challenging for First Son when we read them together and pulled ones on the same lists that I knew we had on the shelves or that I'd read and liked from the library.
Then I discovered the Lexile Framework. I can't say whether it's an adequate measure, really, but I have found some helpful suggestions using the Find a Book feature. Again, I searched for books we were already reading, then used the same range to find new books. What I like best about this particular site is the ability to refine the results using scales on the list for not only reading ability, but age. While not everything they think is appropriate for a six year old is something I think is appropriate for my six year old, it's wonderful to be able to eliminate a great many books we all think are inappropriate for him.
Moving forward, I was still very lenient with what First Son selected to read, but I tried to keep a shelf stocked with books I believed were close to a level that would be challenging (with me sitting beside and helping with any difficult words).
- Mercy Watson Fights Crimeby Kate DiCamillo 
- The Girl Who Loved Wild Horses (Richard Jackson Books (Atheneum Hardcover))by Paul Goble 
- Hot Fudge Heroby Pat Brisson 
- Attack of the Tyrannosaurus (Dinosaur Cove, No. 1)by Rex Stone (This was actually a bit too hard when we first read it together.) 
- Pirates Past Noon (Magic Tree House, No. 4)by Mary Pope Osborne * 
- Night of the Ninjas (Magic Tree House, No. 5)by Mary Pope Osborne * 
- Bertie's Picture Dayby Pat Brisson 
- Midnight on the Moon (Magic Tree House, No. 8)by Mary Pope Osborne * (He read numbers 6 and 7, too, just not during our reading lessons.) 
- The Runaway Bunnyby Margaret Wise Brown 
- Squids Will Be Squids (Picture Puffins)by Jon Scieszka (selected morals) 
- Saturday Night at the Dinosaur Stompby Carol Diggory Shields 
- Ghost Town at Sundown (Magic Tree House)by Mary Pope Osborne * 
- If I Had a Million Onionsby Sheree / Yayo (selected poems) 
 
 
