I can't imagine putting your boat away for the winter in Arizona. Being a Wisconsin native, we would winterize it when the river froze. But, if you are giving it up for the year... It's a good idea to check/change your lower unit grease. Lubricate every cable and anything else that moves and that can be lubricated. New spark plugs will make sure you have that hot spark next July when it is warm enough for you to fish again. Bayou mentioned the gas stabilizer and that is another good thing to do. Inspect everything you can. If something doesn't look right or work right, you may opt to taking it to a shop now instead of waiting and waiting and waiting in the spring.