A very brief daily prayer each day for nine days. For the more ambitious, say a Divine Mercy Chaplet also (I can guide you to some very good ones, audio or video, if interested). There is also a link at the following site.
“Today bring to Me all Devout and Faithful Souls, and immerse them in the ocean of My mercy. These souls brought me consolation on the Way of the Cross. They were a drop of consolation in the midst of an ocean of bitterness.”Read more: http://www.ewtn.com/devotionals/mercy/novena.htm#3#ixzz1rSTKX9V7