Currently Being ModeratedJan 9, 2013 12:04 PM (in response to upctry2)
There are many variables involved in how your friend may want to operate. In the ideal case, where everything is constantly in contact with iCloud via the internet, whenever he saves a file on one device, it's available a short time later on the other iCloud-synced devices. He should attempt to not have the same file open on multiple devices at the same time, or else iCloud will spawn multiple, different, copies of the file and he will have to reconcile the file differences and figure out which is the one to use.
Your friend should also be cautioned to keep the programming and formatting simple because there are some differences in features between the platforms.
Apple has arranged the defaults so that iCloud syncing is the preferred mode. It takes extra steps to save files only locally, so that's a plus for him.