...I'm milking it for another two weeks! Then, mine is getting put away as well. Recommend that you shore up your tires or lift them off the ground, to prevent flat spots. And, throw on a battery tender (or disconnect the battery altogether). Finally, consider putting in just a tad bit of fuel stabilizer and letting it run in for a few... experience with motorcycles has taught me this is a wise thing to do, if you want it to start and run well in the spring.

Beyond that, consult the owner's manual. There is a section dedicated to winterization, and it's pretty good advice.