Regarding rotation- I'm assuming when cutting with the grinding wheel straight up and down- Hold the grinder with the wheel to the left. To rephrase, you want the top of the wheel rotating forward and away from you. In this orientation, the wheel will pull itself along the cut as you cut down and forewards. You do not want the wheel to be pushing itself off the material. This is easier, safer, and greatly extends the life of the wheel.
I recommend a full face shield (I've been known to pull the shade out of my welding mask when grinding in close proximity) leather gloves, non-ripped or frayed denim jeans, and a welding jacket, or button-down denim or heavy cotton long-sleeved shirt or similar.
Some of this may be a bit much when doing a very quick buzz on something, but better safe than hurt. Use your head. Exposed, frayed fabrics ignite a lot easier than intact clothing, and cotton and denim resist sparks a lot better than synthetic fabrics.
Oh, yeah- You ain't lived until you've had a hot weld booger fly down the neck of your shirt, dribble down your chest and past your waistband. I have NEVER dropped my drawers so fast in my LIFE!!! I was s**tin' kittens!