|Stop Kids getting Paid Apps on iPad.|
There's a ten to 15 minute window after you enter your iTunes ID and Password that another One click download can occur without you entering your password again. In that 15 minute purchase window either watch the child carefully or restart the iPad.
Get another iTunes ID for your child, but don't associate a credit card with it. iDevices can have more then one user ID associated with them so your child can use their own one to happily browse the thousands of kid friendly apps and games out there.
Lastly just use the security options on the iPad. There are built in password locks that can stop certain apps and functions being activated without a passcode put in, just activate the security feature under settings to save yourself a fortune in Itunes bills and having hundreds of embarrassing inexplicable apps on your iPad.