Those in the FUNdamentals stage should avoid stimulation 1-2 hours before bed and should limit screen time. A 15-30 minute regular bedtime routine should be reinforced.
In addition parents/caregivers should help children "establish independent sleep initiating behaviours" (Sleep, Recovery, and Human Performance).
The following links point to resources that have been collected and are relevant to this skill (?).
Sleep, Recovery, and Human Performance, is a 20 page pdf document put together by researchers in Calgary for Sport for Life. It discusses the importance of sleep and recovery for sport performance and some of the most prominent sleep disorders and factors that affect one's sleep and recovery. The document is very clearly and consisely written to discuss the key factors across all LTAD stages.