Add two date fields to the table: CreatedDate and ModifiedDate.
On the form where data is added, add text boxes corresponding to these fields. It's your option whether you leave them Visible or not (see the Visible property), but i you leave them Visible you should set their Locked property to Yes so the user can't change them. Then you can use the Form's BeforeUpdate event to set these values. The code would liik something like
If IsNull(Me.CreatedDate) then Me.CreatedDate = Date()
Me.ModifiedDate = Date()
Jim