Edit a page or a post. You should see a meta box below your content area labeled "Plum Code Box". This should have the number of boxes set to one, with the first box showing by default. Paste your code into the box and paste the short code displayed above the box to the right into your page or post. You may set the number of boxes to any number between 1 and 10. The specified number of boxes will be shown with corresponding shortcodes.
Email firstname.lastname@example.org or find me on Twitter at @codeplum.