http://www.imsafe.com/site/water-safety - I'm Safe.com's Water Safety web page includes free lesson plans to share with families and children to develop water safety skills.
http://www.aap.org/healthtopics/watersafety.cfm - According to the American Academy of Pediatrics's Water Safety site, "Drowning is the second leading cause of unintentional injury death for children and adolescents. The AAP has information on how to keep children in all age groups safe in the water at home, in swimming pools, on boats, and in open bodies of water." The AAP's Water Safety site guides families, communities, and professionals to water safety resources and guidelines.
You'll also find several water safety books for children at the Corvallis-Benton County Public Library under the call #J 797.2108. For example:
Near Water by Claire Llewellyn (Barron's Educational Series, 2006) Teaches children the different ways to keep safe when in or near the water.
On a trip to the pool with her mother, Maria notices the various signs that help them, including one that lists the pool hours, two that state safety rules, and several that show the depth of the water.