How to add ventilation to an 8x12 shed I use to work wood?

Why not install a small air conditioner.

Most wood shops install large exhaust fans to control dust levels.

Your idea of cross ventilation would be good for adding fresh air into the space. Sometimes, two windows on adjacent walls (one on each wall) are adequate for cross ventilation. You'll gain better air control with casements than with typical "over/under"windows. You can always supplement with a larger stand fan.

If you have a power source you can get a portable air conditioner/dehumidifier. These units are on rollers and don't install into a window (but you will need to stick the vent/drainage hoses out the door).

If there isn't power then your best bet is to create passive cross ventilation.

What direction do your prevailing winds move? Add windows to opposite sides of the shed to take advantage of those breezes.

I live in Florida winds come from everywhere but an air conditioner is the obvious answer. I have power it’s hard to work on wood with out it. I’m not looking to work climate controlled just cool it off so it’s not so humid in it. I was asking for the people that know how cross ventilation works best and can advise me before I cut holes in my shed side to build a window stool.

If you originally built your shed, it will not be difficult for you to come up with pipes or air conditioning there to not breathe wood dust. My friend works in a carpentry shop. They have no air ducts, and he complains of a strong cough. They ventilate the room by creating drafts from the door and windows, which does not very effectively remove dusty air. I would rebuild the shed in another place or set up an air duct system if I were you. When we were building our workshop, we turned to AJ Mechanical. They build not only new buildings but also sheds workshops and studios.

Get an exhaust fan and put it in the window.