Books about him include Clyde Tombaugh: Discoverer of Planet Pluto, by David H. Levy (Sky Publishing, 2007), and a picture book, Clyde Tombaugh and the Search for Planet X, by Margaret K. Wetterer (Carolrhoda Books, 1996).
Astronomy for Everyone
On the NASA/JPL website, Night Sky Network: Astronomy Outreach and Education, search for astronomy clubs in your area and find out about presentations and events they may offer. The site provides sky-watching resources and indoor and outdoor activities for children and multiage groups.
The Astronomical Society of the Pacific's Family ASTRO program offers a multitude of activities with supporting resources, as well as online games and research tools.