Products that I have mentioned so far are free for personal use. However if you like more support with your software a paid-for app might be right for you. NetNanny have been around for years and should know their stuff by now, they certainly have a very feature-rich offer for those that want to know exactly what their kids have been up to, rather than just blocking the bad guys. This online review has a good run-down of the features.
Net Nanny can be purchased in the UK at http://www.i-technosoft.co.uk/netnanny
(I have no connection with any software provider mentioned in this blog!)