Yes, you need to create a separate library under the master user account. I found the directions to share music between accounts here: http://support.apple.com/kb/HT1203 the same directions apply to sharing apps. In your master account, not for iTunes, just your computer in general, there is a folder named "Public." In that folder there are already files like Public Music, Public Pictures etc. I created a folder in that file called "Public Apps" and dragged apps from my "Itunes Media" file into it. Anything you do not want your kids to have access to keep in the main account and set a password for that account. Then, when your kids go into their iTunes accounts, they should not even be able to 'see' those apps to put on their ipods. They'll only see the ones you give permission for. I hope that makes sense.