By standard, do you mean everyday grooming? For me, that would mean shedding (seasonally), curry, dandy, mane, tail (if not in a bag), face, and hooves. If you're grooming for a show barn, you might be expected to add removing/replacing blankets or sheets, vacuuming, or a rubdown with a towel. You might also want to get comfortable with bathing, if you aren't already.
For special grooming, you could offer mane pulling (Lord knows I hate to do it), braiding/banding, tails, clipping, hoof polishing.
I am useless when asking what to charge, though, sorry.
Learning never stops