A simple way to think about working a parametric EQ is to think of a graphic eq in front of you. Now, if you hold your finger up to the sliders, the "sweep" or frequency control would move your finger left or right (low or high) to choose the center of the frequencies you want to affect. The bandwidth, or "Q" would determine how many sliders you want to move. A really narrow Q might just move one or two whereas a wide Q might make a big curve. Then , the boost/cut control would be how far you wanted to move the sliders.
In reality, a parametric is a lot more precise because you're not limited to preset frequencies like you are on a graphic, I just use the graphic visualization to help make sense of it.
As far as standards, there are none that I know of, It's always whatever the music needs with me. Although, when I find myself making huge EQ changes on the channels, I have to stop and take a serious look at how I tracked that particular track.
