If you are struggling with falling asleep or maintaining sleep, I highly recommend the book 8-Minute Meditation: Quiet Your Mind. Change Your Life. It is written by Victor Davich and not only is it a quick and easy read, it provides the foundation for the coping tools you will need to manage your sleeping difficulties. I always recommend this book for anyone dealing with sleep problems, as well as those learning to manage anxiety and depression. The book provides an 8-week meditation program, which increases in complexity and only requires an 8-minute meditation session a day. I actually need to order some more copies because I'm constantly giving this book away to clients!
If your child is struggling with sleep then I recommend the workbook The Relaxation and Stress Reduction Workbook for Kids: Help for Children to Cope with Stress, Anxiety, and Transitions. This workbook provides great exercises that are developmentally appropriate, and I encourage you to do the workbook together, rather than assigning pages for your child to complete independently. This will provide opportunities for discussion on stress management and allow for you to model healthy coping behaviors. The teen version of the workbook, The Stress Reduction Workbook for Teens: Mindfulness Skills to Help You Deal with Stress, is also useful.
If you find that the sleep difficulties are causing significant impairment or distress in important areas of functioning, such as at work or school, I encourage you to seek assistance. Please do not hesitate to contact me if you have any questions.