I have recently purchased Apple TV and would like to know if there is a way to limit the access that my children have to unsuitable content?

As you have discovered, Apple TV is great fun for all of the family and the good news is that you have complete control over who can view what. By enabling the restrictions (see below) you can determine exactly what can be purchased in the itunes Store, set age ratings for films and TV shows and even block explicit words in books. We would recommend that you take your time to go through each category in turn and carefully consider what restrictions to apply. Once set up the settings can’t be changed unless the passcode is entered again.