" I am completely ignorant when it comes to solar power.

I have a 9vdc 200mA wall-wart for my scanner.

I want to run the scanner off of solar power when I can.

I assume a 12v solar panel will not work, and a 75w panel will be
overkill... I also assume that a handful (6 to be exact) of 1.5v solar
cells
wired together will give me 9v with plenty of mA's to run the scanner.

To power your scanner you could use the 12 volt panels and then a regulator
circuit after them. If you try to use 9 volts , the voltage will change as
to the ammount of light varies on the panel.