Down sawth, we don't do much winterization because we're usually on the water until the first of December and back out in March.
But, winterization would usually consist of changing the oil and filter and replacing the lower unit grease. That's a 30 minute job and requires about zero mechanical knowledge.
Putting the battery on a Battery Tender works great if you have power at the boat, but removing the battery and keeping it inside on a battery maintainer will also substantially lengthen its lifespan. If you have a 2 stroke, also change the spark plugs at season's end.
I never winterized my pontoon in any way, and placed no emphasis on maintaining the lower unit. This year, I found my gear case toasted. I should have been having the lower unit periodically pressure and vacuum tested. And to think that my Yamaha 115 hp 2 stroke lasted 26 years.
But it forced me to buy a new Bennington a year earlier than planned. YAAAA!