Not sure if this is what you really asked for.
Go to System Preferences -> Accounts and use the tab parental control. Or simply type in the spot light field of System Preferences "parental control".
Hope this was what you asked for.
And welcome to the forum.
I was trying to find the file where the results of that process are stored so I can just copy it around to 20 other computers so they'll all have the same settings!
I know that system administration tools exist to do this on a server level but we don't have a MAC server in this computer lab.
Hmmm, here another idea:
change these settings on your local computer. Then go to home/Library/Preferences and list after the date. Check which file was changed most recently. You might want to copy this file to all classrooom computers (if it'S a plist). Not sure if it would work but surely worth to try.
Good luck!
I'm not sure, but wouldn't it be quite stupid of Apple to store a text-file with restrictions for the user in the user's Library, to which he _does_ have access, I believe?