1,2,3 Magic is a good choice. I don't feel it works for everything but it can help get things back on track and help the parent follow through.
How to talk so kids will Listen by Adele Faber is another good one. We actually attended a 7 or 8 week parenting class using her material and found that to be very helpful. So far for DD who is 7 it has been smooth sailing....6 was out toughie!