After writing the last entry, it made me think of some great resources that have helped us in particular with our oldest daughter. She's four and is learning about the Jesus and the Bible.
A catechism written by Christ Schlet (adapted from historical catechisms) for children can be found under The Children's Catechism.
Note that on this link there is a "Catechism for Young Children" but its much longer than we've used so-far. We've simply been using the introductory, 50 question version. It's been great. We've only had to adapt a few phrases, as we hope to introduce some of the theological jargon that she'll eventually face.