Seasonal maintenance on Carrier 9200

Hi All. Been a member here for a few years, but haven't been back in a while. I guess that's a good thing, right? No problems (knock on wood). I'm just wondering what kind of seasonal maintenance tasks I should perform on my Carrier 9200 Weathermaker furnace.

The temps are getting warmer and I suspect that we'll probably shut it down for the season at the end of this month. Before I do that, what should I be doing to make sure the system is maintained and ready to go for the next heating season?

We change the filter before the start of every season. I replaced the pressure switch in late 2007 and it's been running like a champ ever since. I haven't needed them, but I also have a replacement ignitor and flame sensor, just in case. The unit has a humidistat that adds moisture to the forced hot air. We turned it off because it the water would condense on the colder walls in the house and cause streaks.

I'm assuming that I wold do things like: replace the air filter, clean condensate pump tray, ... what else? I feel like I'm missing something? Do I need to do anything with the humidistat? We don't use it, but should it be cleaned or serviced for any reason?

Thanks for any help you can offer.