Unlimited Inquiry
Most children go thru a phase of asking questions about everything - 'why is the sky blue, why do people get old, why..?' In years past time-strapped parents without a clue how to answer such questions would often discourage their youngster with an impatient 'I don't know! No one knows!"
In the Internet age, answering a child's question is as easy as typing it in. Try encouraging unlimited questions about anything and everything (except perhaps age-inappropriate subjects). Before looking it up, ask the child 'How could you find out? How would we know?' and explore the possible answers logically with them (whether or not you actually know the answer doesn't matter). Then take a few minutes to look up what is known, and explain as best you can. You may find yourself learning as much as your child!