Apple provides Parental Controls.
NB:IF you turn these on, then access to many web sites will be disabled until an administrator's name and password are applied.
Here's how to use this feature in OS 10.8.5:
Open system preferences, and select Users and Groups:
Then, enter your administrator password to unlock the panel.
Select the user to set Parental Controls and check the box, enable parental controls.
Then Open Parental Controls for a more detailed look:
Note that there are FIVE tabs across the top. Each one has some settings worth looking at.
If you choose Limit Applications, then give the system a chance to build the window or this won't be effective.
If you choose "try to limit access….." then an administrators name and password will be required for many Web sites that are not really adult sites. This makes using Chrome very challenging at first. Just be prepared to click "allow", enter the admin name and password, and then the site will automatically appear in a "white list" of approved web sites. (what you see under "customize.)
You can allow game center multiple player games or not, limit mail or messages, and check the last field: the parent can choose to get an email when the account user tries to contact someone not on the approved email list.
Time limits can also be enabled. So if the account user wants to play an internet game at 11 in the evening, out of luck……
There are other options. I wouldn't restrict the use of dictation, but I might disable changing password. The administrator of the device has the ability to change that anyway, so this is not a huge issue.