My wife and I share an iMac, and our iPhones keep populating with each other's apps. iTunes keeps trying to update my phone with my wife's apps and data. Is there a way to update the settings on the phone so it can distinguish the difference between App Store accounts?
Easy way: create multiple user accounts on your Mac, a tutorial can be found here.
Hard way: create different iTunes libraries for your user account. You'll need to:
A multi-part tutorial can be found here.