Be sure to figure out the expected spindle RPM. 7" surface grinder types often are 3450, and cups are what they say on the blotter. All wheels should have a blotter on both sides even if you make them out of cereal box material and stuck with dabs of Elmer's glue. Many diamond wheels can run at 5.500 and some higher.
A guard should be in place and still, you should stand not in the blow-up circle.
For cut-off wheels, it is good to have a weak to lock your spindle to tighten wheels because it is easy to crack one trying to hold it by hand.
Wheel spindle nut and flange nut should be as tight as an average strength guy can pull with a wrench about 6 or 7" long with a hand on the wrench and a hand on the wheel...and the nut turning should tighten towards the tightening..as if starting the spindle will tighten both nuts. I like to have a red-mark at the left-hand side to tell everyone that that end is left-hand.
Tc grinder should run right and left for different kinds of cutters. When you run the wrong way you avoid hogging, and be sure the wheel is tight. (Some times you run the wrong way to grind into the edge for carbide, and some times you wrong way to skim off a burr.
Diamond wheels like 4500 to 6500 SFPM (and higher), but will grind OK at 3000 to 4000 with not hogging, slow speed like this can cause more wear to the wheel but is commonly done.
The labeled wheel RPM is often best, and that maximum speed..