I got it! I think.
I must be thick, it took a while, but I think I've figured out how to schedule my military.
Create squads. Apply colorful names. Equip as desired. All that I had, I just had to figure out scheduling. The light bulb came on when I saw what I had been missing in the GUI, the name of the alert level in the title bar, and realized this was the page (schedule) that applied to that alert level. Now it makes sense.
Each alert level has a schedule. Each schedule has, for every squad, for every month, a list of orders. You can assign individual squads to individual alert levels, in which case they'll follow their schedule for the current month for that alert level. Viewing the schedules is done by going to the (m)ilitary screen, then the (s)chedule screen. Mine defaults to showing the Active/Training alert level's schedule. You can - and this was the bit I missed - page through the alerts by hitting (/) (or (*) to go backwards). Each page will show you the whole schedule for that alert - that is, orders for every squad for every month.
Go ahead, do it now - if you haven't done anything with this, you'll page through Inactive and Active/Training, and probably the alert level you set up to restrict civilians to their burrow during a siege. You'll see the title bar change to "Squad Schedules: Active/Training" (with the current alert name, of course).
When you create a new alert (in the (m)ilitary screen, (a)lerts subscreen), you'll get a new page here, with a schedule for that alert.
Each cell in the grid is a summary of the orders for that squad for that month. The actual list of orders for that squad/month - another thing I missed - is down below the grid. Use Tab to switch focus between the grid and the order list. Use o/e/x to order/edit/cancel when in the order list - I was using them from the grid, which confused me because I kept getting 'Mixed' there, not understanding how to edit the list itself.
If you're not making it super-complicated - and I'm not there yet - it's easier to remove and add (cancel and order) than to use edit. Go to the first month in the grid, Tab to the order list, x to cancel each item. Then add with Give (o)rder. That will take you to the order screen.
Cycle through the available tasks by continuing to hit (o). When you get to the activity you want that squad to do for that month, use + or - to adjust the number of soldiers needed to perform the activity. (At least one less than the total number in the squad is preferable, so some number can rotate off to eat/drink/sleep.) When done hit Enter to select, then Shift+Enter to go back. (That confuses me a bit - when you hit Enter, it looks like nothing happens. I'm sure you have to hit it, though.) That will set the orders, with the number soldiers doing it, for that month, when the squad is set to that alert.
Don't forget to set where they sleep by using (s) to cycle through the options. Then use (c)opy, then move to the rest of the months and (p)aste, to get them to do it at any time of year.
Now when you go to the (m)ilitary screen and change a squad's (a)lert level, this is what they'll do.
(Sidetrack - one of the orders available is Patrol Route. This uses a route set up from the main menu Notes command. Hit (N)otes, move cursor, (p)lace points, (n)ame them, add descriptive (t)ext. After you place your points, go to (r)outes, (a)dd route, (e)dit waypoints, then move cursor to a previously placed point and (a)dd waypt for as many points as you want in your route. (n)ame the route, and that name will appear in the Patrol Route orders page to be selected. Also use points to name all your levers
)
An example of what I did after figuring this out was to set a route near my pit. I created a new alert called Pit Patrol, created a route with some points near my mass pitting output, and set orders to patrol that route in the Pit Patrol schedule for my archer squads. Now, when I have live archery targets, all I need to do is set one or more archery squad alert levels to Pit Patrol.
(I hope
It's set up and tested, but I haven't caged anything yet. )
Let me know what you think, or if I missed anything.