Add a date/time field that stamps when the action was taken. When a record is added, the current date and time (based on the user's computer clock) is stored.
For deletions, don't actually delete the record. Instead, mark or flag the record for deletion. If you use a checkbox for that, the date/time stamp would stamp the time the checkbox was clicked.
In the future, when you want to list all active (i.e. those records not marked for deletion) records in a report or listing in a form/subform, filter the report/form to only include those where the checkmark is unchecked (i.e. value FALSE).
Michigan Dept. of Environmental Quality, Air Quality Division