Is there an internet for dummies book they can read?
A filter will not work.
You can do a filter two ways black list or white list, black list the content you want to block but then you would need to know all the content that needs blocking, I hate to say this but the Internets a big scary place full of cat videos, pron and idiots (farcebook/twatter), you can't block everything and while list for the exact same reason.
You could block as you go along but again it's a waste of time.
Unless and the more realistic way of looking at this is they aren't looking out for the kiddies but really they are using that as an excuse to force through the ability to block what they want for everyone at will.