The EQ works like any 3-band EQ - the left slider is for bass, the middle for mid-range and the right slider for treble. Moving the slider up increases the response of the tones and moving the sliders down decreases the response for those tones. Set in the middle - the response will be flat or natural.
The tuner works such that as you tune a particular string, the LED's on the left side of the GREEN LED indicate a flat condition and the LED's on the right side of the GREEN LED indicate a sharp condition. When the GREEN LED lights up - that string is in tune.