In my opinion, two of the best books to read to your children–outside the Bible itself–are The Jesus Storybook Bible and The Big Picture Story Bible. The author of the former acknowledges her debt to Tim Keller; the author of the latter specifically thanks Graeme Goldsworthy.
My 3-year-old daughter loves both of these. They have great illustrations, and they accurately present Scripture as a unified story of redemptive history that culminates in the person and work of Christ.
Both highly recommended.
Update: I should also mention a book by Starr Meade (a gifted Reformed writer): Grandpa’s Box. It’s for an older age group, but it seeks to tell the story of redemptive history in an imaginative way. There is a study guide available as well.