The basic setup is to connect the mic cable from your mic to the XLR (microphone) input in the rear of the unit. Press the MIC IN button on the front panel. While you sing, adjust the MIC GAIN level so that your loudest peaks don't light up the red LED in the front panel meter.
Connect cables from VoiceWorks' left and right output to your mixer and check to make sure the mixer levels are not so loud they cause feedback.
Connect a MIDI keyboard to the rear MIDI input. Set the Keyboard to send on MIDI channel 1. Turn the large wheel to select program number 9 and press Recall. Make sure the bypass button is not lit. Sing into the mic while you play the keyboard. You'll hear your voice plus the harmony.
When you get comfortable with this preset, try the others. Not all presets require keyboard input - a second or two after you have selected a preset, the display will show the preset control method. The ones that require keyboard input are Notes and Chord. The Shift and Scale do not.