Just a quick question and then Ill get back to exploring answers in the forum.

I want to grade a pattern.
Do I have to have all sizes of the pattern already saved, OR
Do I have one pattern perfected in, say a size 10, and then grade from there?

You do not need all drawings of all sizes but you need to know the grading rules(values) for the different sizes.
You can grade in 2 ways:
1. You have your drawing in 2 sizes like size 38 and 40. Then you add grading arrows for each point from one size to the other size. PM calculates the grading values for each poont.
2. You know the grading values. You add all grading arrows and add the grading values for each point.
You can save those values in a grading table which can ve inserted or opened in other drawings.

When you have a graded base model, when you edit the model PM adds with every editing of the drawing new grading arrows. So when you cut, move, rotate a graded pattern you will also have a graded edited pattern.

A bit more clarification: the purpose of the grading feature is to create a nest of different sizes from a single first pattern in a single command. This takes seconds in Patternmaker but would take half a day at a drafting table. But first you have to have the grading size steps defined in the form of those little yellow arrows, and once defined they have to be applied to each new pattern. Defining the first set of grading arrows and checking them for errors is the bulk of the work, after which you can apply them to pattern after pattern. Eugenie's answer refers to two different methods for creating those arrows for the first time.

Thank you!

My brain hurts from trying to figure this out, but it's actually happening!
I will re-read these posts tomorrow and dive in again.
I do have a plotter and that's making things easier.