Q I want to set up a Mac to convert our talking newspaper to digital audio recording and editing, running Audacity or similar to generate output to a memory stick. Once set up, it will run in splendid isolation from the Internet, having only an occasional connection to my MacBook. Will this cause problems?
A No. Macs are quite happy running without network connections. You will now need to set it up whilst connected to the Internet, as it will require access to the App Store to configure and download software updates.
Before disconnecting it from the Internet, open the Date & Time pane in System Preferences, select the Date & Time tab, and set it to not get the time automatically; that will spare it looking for a disconnected time server. Then open the App Store pane, and configure that so that it will not automatically check for updates. Whilst you should try to keep its software up to date every few weeks, applying the latest security updates should be much less critical, as it will not be vulnerable to external intrusion.
Updated from the original, which was first published in MacUser volume 25 issue 23, 2008.