Chapter books feel like "big kid" books, and we want all readers to feel successful. So even if your reader is not quite ready for books like The Magic Tree House, there are chapter books that still have large typeface, lots of white space and lots of illustrations. A typical page in one of the books featured here looks like this:

You can link to the catalog for these titles by clicking the image or the book title.
The Critter Club by Callie Barkley
King and Kayla by Dori Hillestad Butler (also available in Overdrive)
Heidi Heckelbeck and Henry Heckelbeck by Wanda Coven (also available in Overdrive)
Yasmin books by Saadia Faruqi (also available in Overdrive)
Sophie Mouse by Poppy Green
Princess in Black by Shannon Hale (also available in Overdrive)
Good Dog by Cam Higgins
Infamous Ratsos by Kara LaReau (also available in Overdrive)
Judy Moody and Friends by Megan McDonald
Fergus and Zeke by Kate Messner
Captain Awesome by Stan Kirby
Desmond Cole, Ghost Patrol by Andres Miedoso
Kingdom of Wrenly by Jordan Quinn
Mia Mayhem by Kara West (also available in Overdrive)
Any of the books in Scholastic publishing's Branches collection would also be worth a look.
And, as always, your friendly local library staff are happy to help you find just the right books.