Not sure on which apps, games and websites are suitable for your child?
the NSPCC has created a site where information is provided:
This is a tool available to anyone whereby other parents have provided their views about the most popular apps and games and particular in regard to age limits and safety settings.
Additionally, parents can always call the online safety helpline on 0808 8005002 to get advice on anything from the latest social networks to parental controls.
Please also consider that sites such as facebook, twitter and youtube will contain material that has been uploaded by anyone around the world and the providers of these sites are unable to vet, track and monitor all uploads/contributions.