I can't tell you how many times I've gotten the following phone call:
"One of my users deleted something. Can we get it back?"
The answer to which, of course, is yes, provided you have a good backup.
But it is better to shortstop the problem entirely with a little user security. Take away the Delete permission, for instance.
To manage User Security, go to Tools | Users Settings.
This is you GoldMine User List.
Simply double-click on a username to edit it.
Go to the "Access" tab. (You'll notice there is plenty more to play with on the other tabs as well)
Uncheck the "Delete" checkbox in the top left hand corner.
Also keep in mind that if the user has "Master Rights", any settings you make are "trumped" by their Master Rights status.
You may also wish to further limit access, and that is fine. Setting up the perfect mix of Accessibility and Functionality can take some trial and error. And while some security is a good thing, it can definitely cut the other way; too much security can take the "Group" out of "WorkGroup".