Enable time limits for your child's account, limit when and for how long your child can use the computer
Enable parental controls on your child's account - manage Internet usage, Mail and iChat contacts, Computer Time...
How to Open the System Preferences in Mac OS X Leopard
Fully manage your child's parental controls from your other computer
Watch how to restrict web usage for your child
See what websites and applications your child as been using, as well as reading iChat conversations
Limit who your child can receive emails and instant messages from, and more
Use the Simple Finder to only allow specific applications to be available to your child
