In case you haven't seen this great series by Kate DiCamillo, may I introduce the Tales from Deckawoo Drive
I love these books because they fit in that perfect kind of middle ground. They are short chapter books, written at about a third grade reading level, that lower elementary kids can read to themselves or preschool kids can enjoy as longish read alouds. Each book has a different main character, but each one is connected to one particular street - Deckawoo Drive.
You know who else lives on Deckawoo Drive? Mercy Watson! That's right, the Watsons make guest appearances in the books and Mercy gets more than her fair share of toast with a great deal of butter.
Give them a try! You'll love the humorous artwork by Chris Van Dusen. His pictures make the unique characters on Deckawoo Drive feel like family.