Power on the printer (you can tell it's powered on when the blue LED blinks), then power on your CLUE.
The CLUE will wait until it can connect to the printer.
Then, the CLUE's built in display allow you to choose an image to print. (just the image name is shown, not the image itself)
Tap the "A" button to move to the next file in the list. When you reach the end of the list, you'll be sent back to the first file.
Tap the "B" button to send the selected file to the printer. While the print is in progress, button presses are ignored.
When the image is done printing, the CLUE will return to the screen where you can select an image to print.