Should go without saying but the wheels on the one from harbor freight ****. Wore out after cleaning up 3 wheels. i figured for 5 bucks i would try it, never again. Going to follow this and see what the GJ has to say.
You want to true the wheel before you dress the wheel. A dressing stone will true the wheel whereas the star type dressing wheel will crack open and sharpen the wheel. You should use both.
Don't breathe the dust generated while dressing the wheel, and don't let the dust settle on other equipment (I usually dress the wheel outdoors). I usually use a small dressing stick or a wheel-type dresser, depending.