Thinking of filing chapter 13

thinking of filing CH13. What happens when you put down all expenses and Income and the extra money supposely goes to the repayment plan ? Do we continue making our regular payments (expenses) plus give the surplus $ for the trustee to pay the arrearage? Also, we are now on a debt management plan (CareOne) since 4/2007 and is working out fine, do we need to show that in the CH13, and would we have to cancel the debt management plan if we list the unsecure credit cards that are in the debt management plan and let them be pay by the trustee? I am sooo confused!!