Have an I phone and 4 iPads on my account. How do I ensure that work done on apps doesn't override newer work on the same app on a different iPad? Also how do I copy work on apps from one iPad to another? I presume this is all handling through iTunes?
The backups themselves are individual to each device, whether they are in iTunes or iCloud.
The document sharing/syncing that some apps use through iTunes are not. To keep those separate you need separate iCloud accounts.
It is possible to have the same iTunes account and different iCloud accounts on each iPad. It is not possible to have more than one of each at any time, and switching between iCloud accounts is supposed to be limited to a certain number over a certain period of time (can't recall the details at the moment); so hold that in mind when planing what combination of accounts will server your needs.