Set up at least two separate accounts on the machine. One for yourself to act as Administrator, and another account for your child's use that does not act as an administrator. You can do this through System Preferences in the 'Accounts' pane. If your child does not already have a user account, click the 'New User...' button. This will open a form that you will need to fill out with information for the account, name, password, etc. The important step here is to NOT check the box for 'Allow user to administer this computer'. Click OK to create the new user account.
If your child already has their own account, in the 'Accounts' pane of 'System Preferences', choose on his/her user and click on 'Edit User...'. Make sure that the box for 'Allow this user to administer this computer' is NOT checked.
While in the 'Accounts pane, let's turn our attention to the Admin account. You are probably going to want to change this information to match yourself. You should also change the password to something that you child will not know.
If this computer is primarily your child's computer, you may want to use the 'Set Auto Login...' feature of 'Accounts' to login to his/her account at start-up. At least make sure that it does not still log in the Admin account.
As an ongoing precaution you will need to make sure that you do not leave the machine logged in as the Admin when your child is using it, always log out the Administration account.
Once you have set up the non-admin account for your child to use, launch ContentBarrier. Choose the new non-admin user from the drop down menu in ContentBarrier.
You can customize the filtering to be age appropriate for the child. Blocking some sites and not others.
The No Access preset will deny all internet access. The Filtered Access preset will filter all the topics in the filter list.
ContentBarrier X is a great tool for enhancing the rules and guidelines you set for your household. It can help prevent inadvertent displays of questionable content while surfing the web. Like any tool it has the possibility to be misused, broken or circumnavigated. We apologize for not issuing a strong warning about the need to use the MacOS X's built in security in conjunction with its use. But by locking down the computer's security you should find greater piece of mind in its use in helping your children surf responsibly.