changing the fuel filter is a great preventative maintenance measure. not to mention, when your fuel sending unit goes bad if you've kept up with changin the fuel filter, you'll have one more bullet to shoot at the Service guy that tries to pin the faulty sending unit on you.

all of the other things chuck mentioned are easy and way-recommended. [personally, i let the shop drain and fulsh the coolant, but that's because i don't want to worry about what to do with the waste.]

good luck.
david