Thanks for all of the suggestions, it sounds like I need to just need to keep encouraging his interests and wait patiently for the rest to follow.
He's been interested in how electricity works, so maybe I'll get some books and have him figure out a way to work some academics into it. Maybe have him start keeping his own science journal with ideas.
The Egghead books look great, we have some books by Raintree that he;s enjoyed so we'll check Egghead out. We do have some of the Magic Schoolbus books that he has really enjoyed, but shows no interest in reading on his own, yet.
Thanks again!