National Association of School Psychologists President Stephen Brock recently stated the importance of kids getting adequate sleep. He sited this article:

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6430a1.htm?s_cid=mm6430a1_e

Sleep for kids : http://www.sleepforkids.org/html/sheet.html

Parents.com : http://www.parents.com/health/healthy-happy-kids/why-your-kid-needs-sleep/

Lifehacker recently had a post with a parent friendly chart on when to put your kid to bed.

Link: http://lifehacker.com/when-your-child-should-go-to-bed-based-on-age-and-wake-1729319068