The Junior Bible Collection from Master Books is very well done and sure to grab your kids' attention. They are short, yet thorough books aimed at elementary aged readers.
David - The Shepherd Who Became a Great King tells the story of David's life in stages. From the days as a young shepherd and the visit from Samuel to the confrontation by Nathan, we study how these events affected David and how they relate to us today.
The Parables of Jesus - The Teachings of Jesus details five of Jesus' well known parables: The Sower, the Good Samaritan, the Pharisee and the Tax Collector, The Prodigal Son, and the Parable of the Talents. Each story is retold and explained, and each includes modern-day applications. This book even features a summary of life at the time of Jesus.
Both of these books are written in simple, clear language that is easy to understand but does not diminish the meaning of the scripture. They feature excellent examples of relevant classic artwork, as well as beautiful illustrations and photography that enhance understanding.
The authors have included interesting facts alongside the story, but the pages are not cluttered or distracting. I think the Junior Bible Collection books would be appreciated by your kids and be and a great addition to your Bible study curriculum.