Use picture books to teach young writers how to organize plot logically. This article includes examples of basic plot structures, along with picture books that use those structures.
This grid can be used to browse Scholastic's Classroom Books' individual paperback titles organized by Guided Reading, Developmental Reading Assessment (DRA), and Lexile Levels.
Perfection Learning article describing the research supporting the use of high interest/low readability books with struggling readers. Includes examples of their products.