Instruction manuals describing how to operate all Holmes humidifier models are available on the company's website. Instructions may vary slightly depending on the model, but they are generally the same and involve filling the water tank and using the control knobs to choose a moisture level.
To operate a Holmes humidifier, remove the water tank from the main housing, and fill it with cool tap water. After placing the tank back in the main housing, turn the control knob clockwise to start the machine. Adjust the moisture level. Continuing to turn the knob clockwise causes the humidifier to produce less moisture and prolong the run time. To turn off the unit, turn the control knob to the "off" position. Once the tank is empty, unplug the unit, and repeat the process.