As much of a newbie to FMP as I am, I've been able to do this, although I'm using FMP10
I just created fields in the table for CreatedBy, CreationDate, ModifiedBy, and ModifiedDate. Then in the field set-up in database management there are options to have the fields automatically filled in with the user name and computer date, and then the fields are set not to allow changes via the layout.
wow. it is that simple. thanks so much!