Parentzone is designed with families in mind. It is realistic about modern lifestyles and the realities of raising children in a digital age. It is free. You will need to register.
The UK Safer Internet Centre provides resources and advice for families, professionals and young people themselves. The site is well-organised and easy to navigate.
Childnet is a charity that provides lots of up-to-date support and advice for professionals, families and young people themselves.