September 17, 2012, 4:17 PM — Here's how you can use OS X's built-in parental controls to limit web site access for kids on your Mac.
1. Go to System Preferences.
2. Go to Users & Groups.
3. Click on the lock at the bottom right to being making changes.
4. You can choose to add a new account or edit an existing one if your child already has one.
5. Choose the account you want to edit, then make sure that the Enable Parental Controls box is checked.
6. Click the Web tab in Parental Controls.
7. You can choose from the following options:
Allow Unrestricted Access to Websites
Try to Limit Adult Websites Automatically
Allow Access to Only These Websites
8. Choose the option you prefer.
The safest option is to Allow Access to Only These Websites. This filters out all other web sites except the ones you specifically choose to allow.
For more, see the original article at the link below.
5 Tips For Parental Controls On Mac | Hong Kiat